diff --git a/Core/include/Acts/Detector/DetachedTrackingVolume.hpp b/Core/include/Acts/Detector/DetachedTrackingVolume.hpp
index b5bacc5bee828aba72da229f9b551847cabb22ba..59310cb8fab1f83e2358c5a11a29ca011be474aa 100644
--- a/Core/include/Acts/Detector/DetachedTrackingVolume.hpp
+++ b/Core/include/Acts/Detector/DetachedTrackingVolume.hpp
@@ -10,9 +10,7 @@
 // DetachedTrackingVolume.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_DETECTOR_DETACHEDTRACKINGVOLUME_H
-#define ACTS_DETECTOR_DETACHEDTRACKINGVOLUME_H 1
-
+#pragma once
 #include <memory>
 #include "Acts/Layers/Layer.hpp"
 #include "Acts/Layers/PlaneLayer.hpp"
@@ -181,6 +179,4 @@ DetachedTrackingVolume::constituents() const
   return m_constituents;
 }
 
-}  // end of namespace
-
-#endif  // ACTS_DETECTOR_DETACHEDTRACKINGVOLUME_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Detector/DetectorElementBase.hpp b/Core/include/Acts/Detector/DetectorElementBase.hpp
index 337e368831b83de82266444d3ebb04a5b8f9346f..6963d6e1730916ed65a6bf50dab9fc0c9ca7da0b 100644
--- a/Core/include/Acts/Detector/DetectorElementBase.hpp
+++ b/Core/include/Acts/Detector/DetectorElementBase.hpp
@@ -10,9 +10,7 @@
 // DetectorElementBase.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_DETELEMENTBASE_DETELEMENTBASE_H
-#define ACTS_DETELEMENTBASE_DETELEMENTBASE_H 1
-
+#pragma once
 #ifdef ACTS_GEOMETRY_DETELEMENT_PLUGIN
 #include ACTS_GEOMETRY_DETELEMENT_PLUGIN
 #else
@@ -174,6 +172,4 @@ DetectorElementBase::registerNeighbours(
 }
 
 }  // end of ns
-#endif
-
-#endif  // ACTS_GEOMETRY_DETELEMENT_PLUGIN
+#endif
\ No newline at end of file
diff --git a/Core/include/Acts/Detector/GlueVolumesDescriptor.hpp b/Core/include/Acts/Detector/GlueVolumesDescriptor.hpp
index 690e1ef562bfb761cd0bfcbea405537322a50030..4541f8266f99f28ec0eb2fdd8e22f769dd0772e1 100644
--- a/Core/include/Acts/Detector/GlueVolumesDescriptor.hpp
+++ b/Core/include/Acts/Detector/GlueVolumesDescriptor.hpp
@@ -10,9 +10,7 @@
 // GlueVolumesDescriptor.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_DETECTOR_GLUEVOLUMESDESCRIPTOR_H
-#define ACTS_DETECTOR_GLUEVOLUMESDESCRIPTOR_H 1
-
+#pragma once
 #include <map>
 #include <memory>
 #include <vector>
@@ -86,6 +84,4 @@ GlueVolumesDescriptor::glueFaces() const
 
 std::ostream&
 operator<<(std::ostream& sl, const GlueVolumesDescriptor& mprop);
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Detector/TrackingGeometry.hpp b/Core/include/Acts/Detector/TrackingGeometry.hpp
index 3dcbda7344324b8c745a57de3fe31ca199900676..7dc7e7852a8cc2e69e8322efa2ce249204d860e9 100644
--- a/Core/include/Acts/Detector/TrackingGeometry.hpp
+++ b/Core/include/Acts/Detector/TrackingGeometry.hpp
@@ -10,9 +10,7 @@
 // TrackingGeometry.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_DETECTOR_TRACKINGGEOMETRY_H
-#define ACTS_DETECTOR_TRACKINGGEOMETRY_H
-
+#pragma once
 #include "Acts/Utilities/Definitions.hpp"
 #include "Acts/Utilities/GeometrySignature.hpp"
 // STD
@@ -166,6 +164,4 @@ private:
   std::map<std::string, const TrackingVolume*> m_trackingVolumes;
 };
 
-}  // end of namespace
-
-#endif
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Detector/TrackingVolume.hpp b/Core/include/Acts/Detector/TrackingVolume.hpp
index e69e173bf4df22651aeede3cfaee3f8ecac09fdc..f2aaf2f9def487f29c29aba60679b5fc783c7a07 100644
--- a/Core/include/Acts/Detector/TrackingVolume.hpp
+++ b/Core/include/Acts/Detector/TrackingVolume.hpp
@@ -10,9 +10,7 @@
 // TrackingVolume.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_DETECTOR_TRACKINGVOLUME_H
-#define ACTS_DETECTOR_TRACKINGVOLUME_H 1
-
+#pragma once
 #include <map>
 #include <string>
 #include "Acts/Layers/Layer.hpp"
@@ -719,6 +717,4 @@ TrackingVolume::detectorElements() const
   return m_detectorElements;
 }
 
-}  // end of namespace
-
-#endif  // ACTS_DETECTOR_TRACKINGVOLUME_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Digitization/CartesianSegmentation.hpp b/Core/include/Acts/Digitization/CartesianSegmentation.hpp
index 3173c8b01bad292652f28e230d5ae663f18c40c2..4dcaa466a651f43f024ae6dad436d6dd79f5a40f 100644
--- a/Core/include/Acts/Digitization/CartesianSegmentation.hpp
+++ b/Core/include/Acts/Digitization/CartesianSegmentation.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_DIGITIZATION_CARTESIANSEGMENTATION_H
-#define ACTS_DIGITIZATION_CARTESIANSEGMENTATION_H
-
+#pragma once
 #include <memory>
 #include "Acts/Digitization/DigitizationCell.hpp"
 #include "Acts/Digitization/Segmentation.hpp"
@@ -151,6 +149,4 @@ CartesianSegmentation::cell(const Vector2D& position) const
 {
   return cellT<Vector2D>(position);
 }
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Digitization/DigitizationCell.hpp b/Core/include/Acts/Digitization/DigitizationCell.hpp
index ca7861a1acb04963acf97babe71a1ed4e136d253..d3ddf1955a0812966ddb994c5e2496a26abbd26e 100644
--- a/Core/include/Acts/Digitization/DigitizationCell.hpp
+++ b/Core/include/Acts/Digitization/DigitizationCell.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_DIGITIZATION_DIGITIZATIONCELL_H
-#define ACTS_DIGITIZATION_DIGITIZATIONCELL_H
-
+#pragma once
 #include "Acts/Utilities/Definitions.hpp"
 
 namespace Acts {
@@ -94,6 +92,4 @@ struct DigitizationStep
   {
   }
 };
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Digitization/DigitizationModule.hpp b/Core/include/Acts/Digitization/DigitizationModule.hpp
index ad6c0b96bf0eb43326c12540c008d4ec6ec7424f..71014db1daf4d6267d312ce09ed14912982d35d6 100644
--- a/Core/include/Acts/Digitization/DigitizationModule.hpp
+++ b/Core/include/Acts/Digitization/DigitizationModule.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_DIGITIZATION_DIGITIZATIONMODULE_H
-#define ACTS_DIGITIZATION_DIGITIZATIONMODULE_H
-
+#pragma once
 #include <memory>
 #include "Acts/Digitization/DigitizationCell.hpp"
 #include "Acts/Digitization/Segmentation.hpp"
@@ -213,6 +211,4 @@ DigitizationModule::digitizationStep(const Vector3D& start,
   return m_segmentation->digitizationStep(
       start, end, m_halfThickness, m_readoutDirection, m_lorentzAngle);
 }
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Digitization/PlanarModuleCluster.hpp b/Core/include/Acts/Digitization/PlanarModuleCluster.hpp
index 1d238786c20061f3303addd712efd9b75d91f058..3a97c0bf6ba1e58da087b634b9e25c7f62bf1036 100644
--- a/Core/include/Acts/Digitization/PlanarModuleCluster.hpp
+++ b/Core/include/Acts/Digitization/PlanarModuleCluster.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_DIGITIZATION_PLANARMODULECLUSTER_H
-#define ACTS_DIGITIZATION_PLANARMODULECLUSTER_H 1
-
+#pragma once
 #include "Acts/Digitization/DigitizationCell.hpp"
 #include "Acts/EventData/Measurement.hpp"
 #include "Acts/EventData/ParticleDefinitions.hpp"
@@ -80,6 +78,4 @@ PlanarModuleCluster::truthVertices() const
 {
   return m_truthVertices;
 }
-}
-
-#endif  // ACTS_DIGITIZATION_PLANARMODULECLUSTER_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Digitization/PlanarModuleStepper.hpp b/Core/include/Acts/Digitization/PlanarModuleStepper.hpp
index 178dc24e404da51d612e3eb5c91fe7946a823255..0bc05a662e25a7dff855f1087f8b365ae195532e 100644
--- a/Core/include/Acts/Digitization/PlanarModuleStepper.hpp
+++ b/Core/include/Acts/Digitization/PlanarModuleStepper.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_DIGITIZATION_PLANARMODULESTEPPER_H
-#define ACTS_DIGITIZATION_PLANARMODULESTEPPER_H
-
+#pragma once
 #include <memory>
 #include <vector>
 #include "Acts/Digitization/DigitizationCell.hpp"
@@ -95,6 +93,4 @@ private:
   std::unique_ptr<const Logger> m_logger;
 };
 
-}  // end of namespace
-
-#endif  // ACTS_DIGITIZATION_PLANARMODULESTEPPER_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Digitization/Segmentation.hpp b/Core/include/Acts/Digitization/Segmentation.hpp
index 59feafb8cb3a4703f4f9a93a7507d8b2d9cab896..cfeaa49c688e368b610c74bd554638b1ab047a7c 100644
--- a/Core/include/Acts/Digitization/Segmentation.hpp
+++ b/Core/include/Acts/Digitization/Segmentation.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_DIGITIZATION_SEGMENTATION_H
-#define ACTS_DIGITIZATION_SEGMENTATION_H 1
-
+#pragma once
 #include <memory>
 #include <vector>
 #include "Acts/Digitization/DigitizationCell.hpp"
@@ -112,6 +110,4 @@ public:
   virtual const BinUtility&
   binUtility() const = 0;
 };
-}  // end of namespace Acts
-
-#endif
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/ChargePolicy.hpp b/Core/include/Acts/EventData/ChargePolicy.hpp
index 7370ef56844e2f5e4b30d15d08c044dce2411031..581996bf60d23e27c3f6560e2dab2ca90e187666 100644
--- a/Core/include/Acts/EventData/ChargePolicy.hpp
+++ b/Core/include/Acts/EventData/ChargePolicy.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_CHARGEDEFINITION_H
-#define ACTS_CHARGEDEFINITION_H
-
+#pragma once
 namespace Acts {
 
 /// @class ChargedPolicy
@@ -120,6 +118,4 @@ public:
     return 0.;
   }
 };
-}  // end of namespace Acts
-
-#endif  // ACTS_CHARGEPOLICY_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/Measurement.hpp b/Core/include/Acts/EventData/Measurement.hpp
index 844164d27c0df48556ea4767537341c267c56fc0..6984dbbe0c2ac44474d4ba01d69e8ccc199f0f0b 100644
--- a/Core/include/Acts/EventData/Measurement.hpp
+++ b/Core/include/Acts/EventData/Measurement.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_MEASUREMENT_H
-#define ACTS_MEASUREMENT_H
-
+#pragma once
 #include <memory>
 #include <ostream>
 #include <type_traits>
@@ -347,6 +345,4 @@ getSurface(const boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>& m)
   static const SurfaceGetter sg = SurfaceGetter();
   return boost::apply_visitor(sg, m);
 }
-}  // end of namespace Acts
-
-#endif  // ACTS_MEASUREMENT_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/NeutralParameters.hpp b/Core/include/Acts/EventData/NeutralParameters.hpp
index b4ada7d2f22bdd57d5bdb8a6888490babf46c88c..aa31ced5f68402f6e3f2037cf391bfd593a44dc9 100644
--- a/Core/include/Acts/EventData/NeutralParameters.hpp
+++ b/Core/include/Acts/EventData/NeutralParameters.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_NEUTRALPARAMETERS_H
-#define ACTS_NEUTRALPARAMETERS_H 1
-
+#pragma once
 #include "Acts/EventData/ChargePolicy.hpp"
 #include "Acts/EventData/SingleBoundTrackParameters.hpp"
 #include "Acts/EventData/SingleCurvilinearTrackParameters.hpp"
@@ -19,6 +17,4 @@ typedef SingleTrackParameters<NeutralPolicy> NeutralParameters;
 typedef SingleCurvilinearTrackParameters<NeutralPolicy>
                                                   NeutralCurvilinearParameters;
 typedef SingleBoundTrackParameters<NeutralPolicy> NeutralBoundParameters;
-}  // end of namespace Acts
-
-#endif  // ACTS_NEUTRALPARAMETERS_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/ParameterSet.hpp b/Core/include/Acts/EventData/ParameterSet.hpp
index 3f92f95b6f6ca31d8220e68b345d6863413ab63a..c0c18a4b8cf3a2dc3d88a90188ba94037bab2156 100644
--- a/Core/include/Acts/EventData/ParameterSet.hpp
+++ b/Core/include/Acts/EventData/ParameterSet.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_PARAMETERSET_H
-#define ACTS_PARAMETERSET_H 1
-
+#pragma once
 // STL include(s)
 #include <memory>
 #include <type_traits>
@@ -603,6 +601,4 @@ const typename ParameterSet<params...>::Projection_t
     = detail::make_projection_matrix<Acts::NGlobalPars,
                                      static_cast<unsigned int>(
                                          params)...>::init();
-}  // end of namespace Acts
-
-#endif  // ACTS_PARAMETERSET_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/ParticleDefinitions.hpp b/Core/include/Acts/EventData/ParticleDefinitions.hpp
index c85d67c67b99fefbc923bfac9514d8ed66865a65..49a38113a976223f8b051f3c4f81e047f1b908f1 100644
--- a/Core/include/Acts/EventData/ParticleDefinitions.hpp
+++ b/Core/include/Acts/EventData/ParticleDefinitions.hpp
@@ -10,9 +10,7 @@
 // ParticleDefinitions.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_EVENTDATA_PARTICLEDEFINITIONS_H
-#define ACTS_EVENTDATA_PARTICLEDEFINITIONS_H
-
+#pragma once
 #include <vector>
 #include "Acts/Utilities/Definitions.hpp"
 #include "Acts/Utilities/Units.hpp"
@@ -309,6 +307,4 @@ ProcessVertex::addOutgoing(const ParticleProperties& pProperties)
 {
   m_outgoing.push_back(pProperties);
 }
-}
-
-#endif  // ACTS_EVENTDATA_PARTICLEDEFINITIONS_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/SingleBoundTrackParameters.hpp b/Core/include/Acts/EventData/SingleBoundTrackParameters.hpp
index db2161fb2efac18b6d9c8ca07a67835caadef25b..8bc67347b01aad8bb8aa26057ccf3e82a50e0611 100644
--- a/Core/include/Acts/EventData/SingleBoundTrackParameters.hpp
+++ b/Core/include/Acts/EventData/SingleBoundTrackParameters.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_SINGLEBOUNDTRACKPARAMETERS_H
-#define ACTS_SINGLEBOUNDTRACKPARAMETERS_H
-
+#pragma once
 #include "Acts/EventData/SingleTrackParameters.hpp"
 #include "Acts/Surfaces/Surface.hpp"
 
@@ -256,6 +254,4 @@ private:
   const Surface* m_pSurface;
 };
 
-}  // end of namespace Acts
-
-#endif  // ACTS_SINGLEBOUNDTRACKPARAMETERS_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/SingleCurvilinearTrackParameters.hpp b/Core/include/Acts/EventData/SingleCurvilinearTrackParameters.hpp
index 16387994abd5edc7c6a8ab1379b2be7e3ef24a47..795c764699dc6b0ffb85455b9413f4d61160a01b 100644
--- a/Core/include/Acts/EventData/SingleCurvilinearTrackParameters.hpp
+++ b/Core/include/Acts/EventData/SingleCurvilinearTrackParameters.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_SINGLECURVILINEARTRACKPARAMETERS_H
-#define ACTS_SINGLECURVILINEARTRACKPARAMETERS_H
-
+#pragma once
 #include <memory>
 #include "Acts/EventData/SingleTrackParameters.hpp"
 #include "Acts/Surfaces/PlaneSurface.hpp"
@@ -203,6 +201,4 @@ public:
 private:
   PlaneSurface m_upSurface;
 };
-}  // end of namespace Acts
-
-#endif  // ACTS_SINGLECURVILINEARTRACKPARAMETERS_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/SingleTrackParameters.hpp b/Core/include/Acts/EventData/SingleTrackParameters.hpp
index b466030583f80f27a2ab34bd69d407d8862baea3..76b2eef82d54995c0c5dabc8551054f7ad4fe379 100644
--- a/Core/include/Acts/EventData/SingleTrackParameters.hpp
+++ b/Core/include/Acts/EventData/SingleTrackParameters.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_SINGLETRACKPARAMETERS_H
-#define ACTS_SINGLETRACKPARAMETERS_H
-
+#pragma once
 #include <type_traits>
 #include "Acts/EventData/TrackParametersBase.hpp"
 #include "Acts/EventData/detail/coordinate_transformations.hpp"
@@ -221,6 +219,4 @@ protected:
   ActsVectorD<3> m_vPosition;      ///< 3D vector with global position
   ActsVectorD<3> m_vMomentum;      ///< 3D vector with global momentum
 };
-}  // end of namespace Acts
-
-#endif  // ACTS_SINGLETRACKPARAMETERS_h
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/TrackParameters.hpp b/Core/include/Acts/EventData/TrackParameters.hpp
index b98d9406f51fda07ee00e001e03783aa2ee13fcc..7f9d527a402b413147ef5a8fc59c20604ae06bc7 100644
--- a/Core/include/Acts/EventData/TrackParameters.hpp
+++ b/Core/include/Acts/EventData/TrackParameters.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_TRACKPARAMETERS_H
-#define ACTS_TRACKPARAMETERS_H
-
+#pragma once
 #include "Acts/EventData/ChargePolicy.hpp"
 #include "Acts/EventData/SingleBoundTrackParameters.hpp"
 #include "Acts/EventData/SingleCurvilinearTrackParameters.hpp"
@@ -18,6 +16,4 @@ namespace Acts {
 typedef SingleTrackParameters<ChargedPolicy>            TrackParameters;
 typedef SingleCurvilinearTrackParameters<ChargedPolicy> CurvilinearParameters;
 typedef SingleBoundTrackParameters<ChargedPolicy>       BoundParameters;
-}  // end of namespace Acts
-
-#endif  // ACTS_TRACKPARAMETERS_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/TrackParametersBase.hpp b/Core/include/Acts/EventData/TrackParametersBase.hpp
index be2cef0250bcc220807f0a27ab3afecb75e475a6..ca53056c675aa1cf16ca1f80396094a3990b9617 100644
--- a/Core/include/Acts/EventData/TrackParametersBase.hpp
+++ b/Core/include/Acts/EventData/TrackParametersBase.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_PARAMETERSBASE_H
-#define ACTS_PARAMETERSBASE_H 1
-
+#pragma once
 // STL include(s)
 #include <ostream>
 
@@ -189,6 +187,4 @@ protected:
   virtual std::ostream&
   print(std::ostream& out) const;
 };
-}  // end of namespace Acts
-
-#endif  // ACTS_PARAMETERSBASE_h
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/TransportJacobian.hpp b/Core/include/Acts/EventData/TransportJacobian.hpp
index 9bfb788c35057b272625b75c610b84d313eaea0a..5517a915f252b608be53a95d69fd12aa63ff0923 100644
--- a/Core/include/Acts/EventData/TransportJacobian.hpp
+++ b/Core/include/Acts/EventData/TransportJacobian.hpp
@@ -10,9 +10,7 @@
 // TransportJacobian.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_EXTRAPOLATIONUTILS_TRANSPORTJACOBIAN_H
-#define ACTS_EXTRAPOLATIONUTILS_TRANSPORTJACOBIAN_H 1
-
+#pragma once
 #include "Acts/Utilities/Definitions.hpp"
 
 namespace Acts {
@@ -64,6 +62,4 @@ public:
 std::ostream&
 operator<<(std::ostream& sl, const TransportJacobian& jac);
 
-}  // end of namespace
-
-#endif  // ACTS_EXTRAPOLATIONUTILS_TRANSPORTJACOBIAN_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/detail/coordinate_transformations.hpp b/Core/include/Acts/EventData/detail/coordinate_transformations.hpp
index d1aaa8cab6d917ce2593606e1ac28211374b3599..5642601321e20b78a17d7b14805775a7100e5899 100644
--- a/Core/include/Acts/EventData/detail/coordinate_transformations.hpp
+++ b/Core/include/Acts/EventData/detail/coordinate_transformations.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_COORDINATE_TRANSFORMATIONS_H
-#define ACTS_COORDINATE_TRANSFORMATIONS_H 1
-
+#pragma once
 // ACTS includes
 #include <cmath>
 #include "Acts/Surfaces/Surface.hpp"
@@ -88,6 +86,4 @@ namespace detail {
 }  // end of namespace detail
 /// @endcond
 }  // end of namespace Acts
-#endif  // ACTS_COORDINATE_TRANSFORM_PLUGIN
-
-#endif  // ACTS_COORDINATE_TRANSFORMATIONS_H
+#endif  // ACTS_COORDINATE_TRANSFORM_PLUGIN
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/detail/fittable_type_generator.hpp b/Core/include/Acts/EventData/detail/fittable_type_generator.hpp
index f541535ae968f12de1c70624abb0b1bd1a6eaa65..9e0bb1af0485b91b78b28bac8d02efd2f70b6222 100644
--- a/Core/include/Acts/EventData/detail/fittable_type_generator.hpp
+++ b/Core/include/Acts/EventData/detail/fittable_type_generator.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_FITTABLE_TYPE_GENERATOR_H
-#define ACTS_FITTABLE_TYPE_GENERATOR_H 1
-
+#pragma once
 // boost include(s)
 #include <boost/mpl/vector.hpp>
 #include <boost/variant.hpp>
@@ -161,6 +159,4 @@ namespace detail {
   /// @endcond
 }  // end of namespace details
 /// @endcond
-}  // end of namespace Acts
-
-#endif  // ACTS_FITTABLE_TYPE_GENERATOR_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/detail/full_parameter_set.hpp b/Core/include/Acts/EventData/detail/full_parameter_set.hpp
index d2556d6421989596ccac98e2b23bd93bced8ea59..901ed74eb465a0ec620c93302fbefa111afa1704 100644
--- a/Core/include/Acts/EventData/detail/full_parameter_set.hpp
+++ b/Core/include/Acts/EventData/detail/full_parameter_set.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_FULL_PARAMETER_SET_H
-#define ACTS_FULL_PARAMETER_SET_H 1
-
+#pragma once
 // STL include(s)
 #include <type_traits>
 #include <utility>
@@ -72,6 +70,4 @@ namespace detail {
   };
 }  // end of namespace detail
 /// @endcond
-}  // end of namespace Acts
-
-#endif  // ACTS_FULL_PARAMETER_SET_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/detail/initialize_parameter_set.hpp b/Core/include/Acts/EventData/detail/initialize_parameter_set.hpp
index e68bc340e3d40d607a95b9edebc4b2ef810256f8..da83f9f44bc12680cf320dfa4ce61cbada7216ca 100644
--- a/Core/include/Acts/EventData/detail/initialize_parameter_set.hpp
+++ b/Core/include/Acts/EventData/detail/initialize_parameter_set.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_INITIALIZE_PARAMETER_SET_H
-#define ACTS_INITIALIZE_PARAMETER_SET_H 1
-
+#pragma once
 namespace Acts {
 /// @cond detail
 namespace detail {
@@ -80,5 +78,4 @@ namespace detail {
   /// @endcond
 }  // end of namespace detail
 /// @endcond
-}  // end of namespace Acts
-#endif  // ACTS_INITIALIZE_PARAMETER_SET_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/detail/make_projection_matrix.hpp b/Core/include/Acts/EventData/detail/make_projection_matrix.hpp
index 82fbc743cb34e732fcfa4faa0103c32c8b6fa944..29ab64200105a5f09d6c75b2418cdd3c28603bcf 100644
--- a/Core/include/Acts/EventData/detail/make_projection_matrix.hpp
+++ b/Core/include/Acts/EventData/detail/make_projection_matrix.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_MAKE_PROJECTION_MATRIX_H
-#define ACTS_MAKE_PROJECTION_MATRIX_H 1
-
+#pragma once
 // ACTS include(s)
 #include "Acts/Utilities/Definitions.hpp"
 
@@ -68,6 +66,4 @@ namespace detail {
   /// @endcond
 }  // end of namespace detail
 /// @endcond
-}  // end of namespace Acts
-
-#endif  // ACTS_MAKE_PROJECTION_MATRIX_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/detail/residual_calculator.hpp b/Core/include/Acts/EventData/detail/residual_calculator.hpp
index cf3589eb6a8f8bde3e14d0098b2df089a6fb8bfe..19aac650beecceaae338cc9e23a8434bfd0e303e 100644
--- a/Core/include/Acts/EventData/detail/residual_calculator.hpp
+++ b/Core/include/Acts/EventData/detail/residual_calculator.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_RESIDUAL_CALCULATOR_H
-#define ACTS_RESIDUAL_CALCULATOR_H 1
-
+#pragma once
 // ACTS include(s)
 #include "Acts/Utilities/Definitions.hpp"
 #include "Acts/Utilities/ParameterDefinitions.hpp"
@@ -74,6 +72,4 @@ namespace detail {
   /// @endcond
 }  // end of namespace detail
 /// @endcond
-}  // end of namespace Acts
-
-#endif  // ACTS_RESIDUAL_CALCULATOR_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/EventData/detail/value_corrector.hpp b/Core/include/Acts/EventData/detail/value_corrector.hpp
index bb4d4bf221afe9cc7e21fbcf9ff7847876273a47..05bc92fbec852d009965aa3dcb71866f8b1b8b87 100644
--- a/Core/include/Acts/EventData/detail/value_corrector.hpp
+++ b/Core/include/Acts/EventData/detail/value_corrector.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_VALUE_CORRECTOR_H
-#define ACTS_VALUE_CORRECTOR_H 1
-
+#pragma once
 // ACTS include(s)
 #include "Acts/Utilities/Definitions.hpp"
 #include "Acts/Utilities/ParameterDefinitions.hpp"
@@ -77,6 +75,4 @@ namespace detail {
   /// @endcond
 }  // end of namespace detail
 /// @endcond
-}  // end of namespace Acts
-
-#endif  // ACTS_VALUE_CORRECTOR_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Fitter/KalmanFitter.hpp b/Core/include/Acts/Fitter/KalmanFitter.hpp
index 0fed98b9f392daf652c973966a634ef11f6a856a..4902a26c032ff6a8dca980e1967e8aabd07d37bb 100644
--- a/Core/include/Acts/Fitter/KalmanFitter.hpp
+++ b/Core/include/Acts/Fitter/KalmanFitter.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_KALMANFITTER_H
-#define ACTS_KALMANFITTER_H 1
-
+#pragma once
 // STL include(s)
 #include <list>
 #include <memory>
@@ -235,6 +233,4 @@ public:
   Updator        m_oUpdator;
 };
 
-}  // end of namespace Acts
-
-#endif  // ACTS_KALMANFITTER_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Fitter/KalmanUpdator.hpp b/Core/include/Acts/Fitter/KalmanUpdator.hpp
index e012a0bb64c137cd7ba8378ab3c428866dc60ae1..cb05a8a742e7693566f9b09e300b9cf4acba37b4 100644
--- a/Core/include/Acts/Fitter/KalmanUpdator.hpp
+++ b/Core/include/Acts/Fitter/KalmanUpdator.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_KALMANUPDATOR_H
-#define ACTS_KALMANUPDATOR_H 1
-
+#pragma once
 // STL include(s)
 #include <memory>
 
@@ -79,6 +77,4 @@ private:
   };
 };
 
-}  // end of namespace Acts
-
-#endif  // ACTS_KALMANUPDATOR_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Layers/ConeLayer.hpp b/Core/include/Acts/Layers/ConeLayer.hpp
index ac38699195c40af87ac139420a73ca50850667a3..8bf55a883ebe9eda51cdbfccfb790007484d39d9 100644
--- a/Core/include/Acts/Layers/ConeLayer.hpp
+++ b/Core/include/Acts/Layers/ConeLayer.hpp
@@ -10,9 +10,7 @@
 // ConeLayer.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_LAYERS_CONELAYER_H
-#define ACTS_LAYERS_CONELAYER_H
-
+#pragma once
 #include <algorithm>
 #include "Acts/Layers/Layer.hpp"
 #include "Acts/Surfaces/ConeSurface.hpp"
@@ -106,6 +104,4 @@ protected:
   ConeLayer(const ConeLayer& cla, const Transform3D& shift);
 };
 
-}  // end of namespace
-
-#endif  // TRKGEOMETY_CONELAYER_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Layers/CylinderLayer.hpp b/Core/include/Acts/Layers/CylinderLayer.hpp
index 357c5364685e8563169b2f998b92c6dc51a49b63..eb3a2e72f5c0b561a1e8d3bb6852bf78422bfabd 100644
--- a/Core/include/Acts/Layers/CylinderLayer.hpp
+++ b/Core/include/Acts/Layers/CylinderLayer.hpp
@@ -10,9 +10,7 @@
 // CylinderLayer.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_LAYERS_CYLINDERLAYER_H
-#define ACTS_LAYERS_CYLINDERLAYER_H
-
+#pragma once
 #include <algorithm>
 #include "Acts/Layers/Layer.hpp"
 #include "Acts/Surfaces/CylinderSurface.hpp"
@@ -134,6 +132,4 @@ protected:
   CylinderLayer(const CylinderLayer& cla, const Transform3D& shift);
 };
 
-}  // namespace Acts
-
-#endif  // ACTS_LAYERS_CYLINDERLAYER_H
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Layers/DiscLayer.hpp b/Core/include/Acts/Layers/DiscLayer.hpp
index 9ab68e12743740c52339fa41d6d2dd30914ccf2b..7ebd946cb691332aefc9c217d8f999ee076c7fe4 100644
--- a/Core/include/Acts/Layers/DiscLayer.hpp
+++ b/Core/include/Acts/Layers/DiscLayer.hpp
@@ -10,9 +10,7 @@
 // DiscLayer.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_LAYERS_DISCLAYER_H
-#define ACTS_LAYERS_DISCLAYER_H 1
-
+#pragma once
 class MsgStream;
 
 #include <algorithm>
@@ -122,6 +120,4 @@ protected:
   DiscLayer(const DiscLayer& cla, const Transform3D& tr);
 };
 
-}  // end of namespace
-
-#endif  // ACTS_LAYERS_DISCLAYER_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Layers/GenericApproachDescriptor.hpp b/Core/include/Acts/Layers/GenericApproachDescriptor.hpp
index 3ed9151e441b8524fc1353fa3ded7a9e77e10efd..9db3ebf59515c94791f02fb35f7a87e9fdb1936b 100644
--- a/Core/include/Acts/Layers/GenericApproachDescriptor.hpp
+++ b/Core/include/Acts/Layers/GenericApproachDescriptor.hpp
@@ -10,9 +10,7 @@
 // GenericApproachDescriptor.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_DETECTOR_GENERICAPPROPACHDESCRIPTOR_H
-#define ACTS_DETECTOR_GENERICAPPROPACHDESCRIPTOR_H 1
-
+#pragma once
 #include <algorithm>
 #include "Acts/Utilities/ApproachDescriptor.hpp"
 
@@ -150,6 +148,4 @@ GenericApproachDescriptor<T>::containedSurfaces()
 {
   return m_surfacesCache;
 }
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Layers/Layer.hpp b/Core/include/Acts/Layers/Layer.hpp
index b7fd21b1a0c52b3a3d0f8deb401e240a4d51e4e8..77d26f56cf11c14405a5e32f7e1a15186e4b1ed3 100644
--- a/Core/include/Acts/Layers/Layer.hpp
+++ b/Core/include/Acts/Layers/Layer.hpp
@@ -10,9 +10,7 @@
 // Layer.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_DETECTOR_LAYER_H
-#define ACTS_DETECTOR_LAYER_H 1
-
+#pragma once
 // Core module
 #include <map>
 #include "Acts/EventData/NeutralParameters.hpp"
@@ -545,6 +543,4 @@ typedef BinnedArray<LayerPtr> LayerArray;
 
 }  // end of namespace
 
-#include "Acts/Layers/detail/Layer.ipp"
-
-#endif  // ACTS_DETECTOR_LAYER_H
+#include "Acts/Layers/detail/Layer.ipp"
\ No newline at end of file
diff --git a/Core/include/Acts/Layers/NavigationLayer.hpp b/Core/include/Acts/Layers/NavigationLayer.hpp
index 8943ed995088052c02c2f8eaacc13cbbfd5c3086..4639d3804d4eb6acb0e7e667847284d555b0fd15 100644
--- a/Core/include/Acts/Layers/NavigationLayer.hpp
+++ b/Core/include/Acts/Layers/NavigationLayer.hpp
@@ -10,9 +10,7 @@
 // NavigationLayer.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_LAYERS_NAVIGATIONLAYER_H
-#define ACTS_LAYERS_NAVIGATIONLAYER_H
-
+#pragma once
 #include "Acts/Layers/Layer.hpp"
 #include "Acts/Utilities/BinnedArray.hpp"
 #include "Acts/Utilities/Definitions.hpp"
@@ -148,6 +146,4 @@ NavigationLayer::isOnLayer(const Vector3D&      gp,
   return m_surfaceRepresentation->isOnSurface(gp, bcheck);
 }
 
-}  // end of namespace
-
-#endif  // ACTS_LAYERS_NAVIGATIONLAYER_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Layers/PlaneLayer.hpp b/Core/include/Acts/Layers/PlaneLayer.hpp
index b5e7bf32780d595ecbb12579e5ad1a62bfd05070..8d631bd5396b3135c78afb5fbd26542178347cfa 100644
--- a/Core/include/Acts/Layers/PlaneLayer.hpp
+++ b/Core/include/Acts/Layers/PlaneLayer.hpp
@@ -10,9 +10,7 @@
 // PlaneLayer.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_LAYERS_PLANELAYER_H
-#define ACTS_LAYERS_PLANELAYER_H
-
+#pragma once
 #include <algorithm>
 #include "Acts/Layers/Layer.hpp"
 #include "Acts/Surfaces/PlaneSurface.hpp"
@@ -108,6 +106,4 @@ protected:
   PlaneLayer(const PlaneLayer& pla, const Transform3D& shift);
 };
 
-}  // end of namespace
-
-#endif  // ACTS_LAYERS_PLANELAYER_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Layers/ProtoLayer.hpp b/Core/include/Acts/Layers/ProtoLayer.hpp
index 0db7088e24e2ee07254b0815e9cae9318294d483..99f286c605d505cc21fbd93f4dd2438aa2e887b9 100644
--- a/Core/include/Acts/Layers/ProtoLayer.hpp
+++ b/Core/include/Acts/Layers/ProtoLayer.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_LAYERS_PROTOLAYER_H
-#define ACTS_LAYERS_PROTOLAYER_H 1
-
+#pragma once
 #include <iostream>
 #include "Acts/Surfaces/PlanarBounds.hpp"
 #include "Acts/Surfaces/Surface.hpp"
@@ -69,6 +67,4 @@ public:
   double
   radialDistance(const Vector3D& pos1, const Vector3D& pos2) const;
 };
-}  // namespace Acts
-
-#endif  // ACTS_LAYERS_PROTOLAYER_H
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/MagneticField/ConstantBField.hpp b/Core/include/Acts/MagneticField/ConstantBField.hpp
index 3719278b1a34c6a9de229ae6e790363a8ce5c8b2..3c56529edd1b549d24ccad4470cc59a50835a30c 100644
--- a/Core/include/Acts/MagneticField/ConstantBField.hpp
+++ b/Core/include/Acts/MagneticField/ConstantBField.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_MAGNETICFIELD_CONSTANTBFIELD_H
-#define ACTS_MAGNETICFIELD_CONSTANTBFIELD_H 1
-
+#pragma once
 #include "Acts/MagneticField/concept/AnyFieldLookup.hpp"
 #include "Acts/Utilities/Definitions.hpp"
 
@@ -165,6 +163,4 @@ private:
   /// The field cell
   FieldCell m_fieldCell;
 };
-}  // end of namespace Acts
-
-#endif  //> ! ACTS_MAGNETICFIELD_CONSTANTBFIELD_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/MagneticField/SharedBFieldMap.hpp b/Core/include/Acts/MagneticField/SharedBFieldMap.hpp
index c0965e2b3b9cc0e38da930b0261ea9d71334b124..d66ca934b9548ea1775a89a730855135c244f3eb 100644
--- a/Core/include/Acts/MagneticField/SharedBFieldMap.hpp
+++ b/Core/include/Acts/MagneticField/SharedBFieldMap.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_MAGNETICFIELD_SHAREDBFIELD_H
-#define ACTS_MAGNETICFIELD_SHAREDBFIELD_H
-
+#pragma once
 #include "Acts/MagneticField/concept/AnyFieldLookup.hpp"
 #include "Acts/Utilities/Definitions.hpp"
 
@@ -71,6 +69,4 @@ private:
   std::shared_ptr<const BField> m_bField;
 };
 
-}  // namespace Acts
-
-#endif  // ACTS_MAGNETICFIELD_SHAREDBFIELD_H
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Material/BinnedSurfaceMaterial.hpp b/Core/include/Acts/Material/BinnedSurfaceMaterial.hpp
index b1eacb7f9142be0ce383c05d5ac820bf19985f8b..102fea20ed701faa8a9459b93f7056485bb672f1 100644
--- a/Core/include/Acts/Material/BinnedSurfaceMaterial.hpp
+++ b/Core/include/Acts/Material/BinnedSurfaceMaterial.hpp
@@ -10,9 +10,7 @@
 // BinnedSurfaceMaterial.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_MATERIAL_BINNEDSURFACEMATERIAL_H
-#define ACTS_MATERIAL_BINNEDSURFACEMATERIAL_H 1
-
+#pragma once
 #include "Acts/Material/MaterialProperties.hpp"
 #include "Acts/Material/SurfaceMaterial.hpp"
 #include "Acts/Utilities/BinUtility.hpp"
@@ -159,6 +157,4 @@ BinnedSurfaceMaterial::entries() const
 {
   return m_entries;
 }
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Material/HomogeneousSurfaceMaterial.hpp b/Core/include/Acts/Material/HomogeneousSurfaceMaterial.hpp
index cf4c50c4e6b931249509db8070f828b35364c9a6..0402565547603ed989acb539786a7edacda6b6ff 100644
--- a/Core/include/Acts/Material/HomogeneousSurfaceMaterial.hpp
+++ b/Core/include/Acts/Material/HomogeneousSurfaceMaterial.hpp
@@ -10,9 +10,7 @@
 // HomogeneousSurfaceMaterial.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_MATERIAL_HOMOGENOUSLAYERMATERIAL_H
-#define ACTS_MATERIAL_HOMOGENOUSLAYERMATERIAL_H
-
+#pragma once
 #include <vector>
 #include "Acts/Material/MaterialProperties.hpp"
 #include "Acts/Material/SurfaceMaterial.hpp"
@@ -112,6 +110,4 @@ inline const MaterialProperties*
   return (&m_fullMaterial);
 }
 
-}  // end of namespace
-
-#endif
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Material/Material.hpp b/Core/include/Acts/Material/Material.hpp
index 9f33c22ee800dfe470777798db31f76ca925ee9b..984b5f72212c2d1a5391cdbf053563fffcfc086b 100644
--- a/Core/include/Acts/Material/Material.hpp
+++ b/Core/include/Acts/Material/Material.hpp
@@ -10,9 +10,7 @@
 // Material.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_MATERIAL_MATERIAL_H
-#define ACTS_MATERIAL_MATERIAL_H
-
+#pragma once
 #include <algorithm>
 #include <climits>
 #include <iomanip>
@@ -313,6 +311,4 @@ private:
   /// optional composition parameter
   MaterialComposition m_composition;
 };
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Material/MaterialProperties.hpp b/Core/include/Acts/Material/MaterialProperties.hpp
index 47a3d165c88283611f54ce7757fe3ba52d0191d3..5c7d8d2952996d07676cf0abcf37c6f133b90670 100644
--- a/Core/include/Acts/Material/MaterialProperties.hpp
+++ b/Core/include/Acts/Material/MaterialProperties.hpp
@@ -10,9 +10,7 @@
 // MaterialProperties.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_MATERIAL_MATERIALPROPERTIES_H
-#define ACTS_MATERIAL_MATERIALPROPERTIES_H
-
+#pragma once
 // Geometry module
 #include "Acts/Material/Material.hpp"
 // STD/STL
@@ -236,6 +234,4 @@ operator<<(std::ostream& sl, const MaterialProperties& mprop);
 typedef std::vector<MaterialProperties*>      MaterialPropertiesVector;
 typedef std::vector<MaterialPropertiesVector> MaterialPropertiesMatrix;
 
-}  // end of namespace
-
-#endif  // ACTS_DETECTOR_MATERIALPROPERTIES_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Material/SurfaceMaterial.hpp b/Core/include/Acts/Material/SurfaceMaterial.hpp
index 82046be511b1aa67cc17a096005b47d5afcf5d67..c4d3870adc48ffe4fe0775355129e1d2e5a95ecf 100644
--- a/Core/include/Acts/Material/SurfaceMaterial.hpp
+++ b/Core/include/Acts/Material/SurfaceMaterial.hpp
@@ -10,9 +10,7 @@
 // SurfaceMaterial.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_MATERIAL_SURFACEMATERIAL_H
-#define ACTS_MATERIAL_SURFACEMATERIAL_H
-
+#pragma once
 #include <memory>
 #include <vector>
 #include "Acts/Material/MaterialProperties.hpp"
@@ -107,6 +105,4 @@ operator<<(std::ostream& sl, const SurfaceMaterial& sm);
 
 typedef std::pair<GeometryID, SurfaceMaterial*> IndexedSurfaceMaterial;
 
-}  // end of namespace
-
-#endif  // ACTS_MATERIAL_SURFACEMATERIAL_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Material/SurfaceMaterialProxy.hpp b/Core/include/Acts/Material/SurfaceMaterialProxy.hpp
index 108a673d77b3c9d14a0c9a8dc27c738b6859079f..48db273e5423ecf0d8f752f985b451e2a4c8f25c 100644
--- a/Core/include/Acts/Material/SurfaceMaterialProxy.hpp
+++ b/Core/include/Acts/Material/SurfaceMaterialProxy.hpp
@@ -10,9 +10,7 @@
 // SurfaceMaterialProxy.hpp, ACTS project MaterialPlugins
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_MATERIAL_SURFACEMATERIALPROXY_H
-#define ACTS_MATERIAL_SURFACEMATERIALPROXY_H
-
+#pragma once
 #include "Acts/Material/SurfaceMaterial.hpp"
 #include "Acts/Utilities/BinUtility.hpp"
 
@@ -122,6 +120,4 @@ inline const Acts::BinUtility*
 Acts::SurfaceMaterialProxy::binUtility() const
 {
   return m_binUtility.get();
-}
-
-#endif  // ACTS_MATERIAL_SURFACEMATERIALPROXY_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Propagator/AbortList.hpp b/Core/include/Acts/Propagator/AbortList.hpp
index dd8cbf69ad445b16a89e1d4e731db16c35aa6a37..4feec7713f5bc2bff4d7bfd78817620f0ab8581a 100644
--- a/Core/include/Acts/Propagator/AbortList.hpp
+++ b/Core/include/Acts/Propagator/AbortList.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_ABORT_LIST_HPP
-#define ACTS_ABORT_LIST_HPP 1
-
+#pragma once
 #include "Acts/Propagator/ActionList.hpp"
 #include "Acts/Propagator/detail/Extendable.hpp"
 #include "Acts/Propagator/detail/abort_condition_signature_check.hpp"
@@ -56,6 +54,4 @@ public:
   }
 };
 
-}  // namespace Acts
-
-#endif  // ACTS_ABORT_LIST_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Propagator/ActionList.hpp b/Core/include/Acts/Propagator/ActionList.hpp
index 82e68fefc41bb552e5ab1ba5e530c1708b2fe3fb..de7d8efeaf00d4b26aef2cd1c412939a9070abff 100644
--- a/Core/include/Acts/Propagator/ActionList.hpp
+++ b/Core/include/Acts/Propagator/ActionList.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_ACTION_LIST_HPP
-#define ACTS_ACTION_LIST_HPP
-
+#pragma once
 #include "Acts/Propagator/detail/Extendable.hpp"
 #include "Acts/Propagator/detail/action_list_implementation.hpp"
 #include "Acts/Propagator/detail/action_signature_check.hpp"
@@ -64,6 +62,4 @@ public:
   }
 };
 
-}  // namespace Acts
-
-#endif  // ACTS_ACTION_LIST_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Propagator/EigenStepper.hpp b/Core/include/Acts/Propagator/EigenStepper.hpp
index d60fcdf98f679cbc74ef10c86e3f1061b4ec21db..9dd8e33ee47ec07a37d6e0f5b1376355551ef2d3 100644
--- a/Core/include/Acts/Propagator/EigenStepper.hpp
+++ b/Core/include/Acts/Propagator/EigenStepper.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_EIGEN_STEPPER_HPP
-#define ACTS_EIGEN_STEPPER_HPP 1
-
+#pragma once
 #include <cmath>
 #include "Acts/EventData/TrackParameters.hpp"
 #include "Acts/MagneticField/concept/AnyFieldLookup.hpp"
@@ -495,6 +493,4 @@ private:
   BField m_bField;
 };
 
-}  // namespace Acts
-
-#endif  // ACTS_EIGEN_STEPPER_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Propagator/Propagator.hpp b/Core/include/Acts/Propagator/Propagator.hpp
index 64a235bd5f73f029d449e19493ec8e64655cdfa8..14ff95fc37d4873566c33706fff7aa5fe93ef24a 100644
--- a/Core/include/Acts/Propagator/Propagator.hpp
+++ b/Core/include/Acts/Propagator/Propagator.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_EXTRAPOLATION_PROPAGATOR_H
-#define ACTS_EXTRAPOLATION_PROPAGATOR_H 1
-
+#pragma once
 #include <cmath>
 #include <memory>
 #include <type_traits>
@@ -371,6 +369,4 @@ namespace propagation {
 
 }  // namespace propagation
 
-}  // namespace Acts
-
-#endif  // ACTS_EXTRAPOLATION_PROPAGATOR_H
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Propagator/detail/Extendable.hpp b/Core/include/Acts/Propagator/detail/Extendable.hpp
index 66fcae2527662e2e3b0e882b5f68ce77ba0fd176..ead1685538538a6216ccf7089cb4241839f78cfa 100644
--- a/Core/include/Acts/Propagator/detail/Extendable.hpp
+++ b/Core/include/Acts/Propagator/detail/Extendable.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_EXTENDABLE_HPP
-#define ACTS_EXTENDABLE_HPP
-
+#pragma once
 #include <tuple>
 #include <type_traits>
 #include "Acts/Utilities/detail/MPL/all_of.hpp"
@@ -69,5 +67,4 @@ namespace detail {
 
 }  // namespace detail
 
-}  // namespace Acts
-#endif  // ACTS_EXTENDABLE_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Propagator/detail/abort_condition_signature_check.hpp b/Core/include/Acts/Propagator/detail/abort_condition_signature_check.hpp
index 206447e617311e983ace0d2da001bf03cf596d9f..c15a77ccb77aeacd13335d28dfc5ff7b55313d44 100644
--- a/Core/include/Acts/Propagator/detail/abort_condition_signature_check.hpp
+++ b/Core/include/Acts/Propagator/detail/abort_condition_signature_check.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_ABORT_CONDITION_SIGNATURE_CHECK_HPP
-#define ACTS_ABORT_CONDITION_SIGNATURE_CHECK_HPP 1
-
+#pragma once
 #include <type_traits>
 #include "Acts/Propagator/detail/condition_uses_result_type.hpp"
 #include "Acts/Utilities/detail/MPL/type_collector.hpp"
@@ -93,5 +91,4 @@ namespace detail {
       = abort_condition_signature_check<T, cache_t>::value;
 }  // namespace detail
 
-}  // namespace Acts
-#endif  // ACTS_ABORT_CONDITION_SIGNATURE_CHECK_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Propagator/detail/abort_list_implementation.hpp b/Core/include/Acts/Propagator/detail/abort_list_implementation.hpp
index 0bac72cb4703d53f4dceac7c869990d7fc90a5c9..d2df9137193cd8dc356c3ff09507c3235a138650 100644
--- a/Core/include/Acts/Propagator/detail/abort_list_implementation.hpp
+++ b/Core/include/Acts/Propagator/detail/abort_list_implementation.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_ABORT_LIST_IMPLEMENTATION_HPP
-#define ACTS_ABORT_LIST_IMPLEMENTATION_HPP
-
+#pragma once
 #include <algorithm>
 #include "Acts/Propagator/detail/condition_uses_result_type.hpp"
 #include "Acts/Utilities/detail/MPL/type_collector.hpp"
@@ -104,5 +102,4 @@ namespace detail {
 
 }  // namespace
 
-}  // namespace Acts
-#endif  // ACTS_ABORT_LIST_IMPLEMENTATION_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Propagator/detail/action_list_implementation.hpp b/Core/include/Acts/Propagator/detail/action_list_implementation.hpp
index 2f6fde29d14c02636cd16eda0cfd677c1297329b..b4af936c8d9519da142e4027c198798b54eb424f 100644
--- a/Core/include/Acts/Propagator/detail/action_list_implementation.hpp
+++ b/Core/include/Acts/Propagator/detail/action_list_implementation.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_ACTION_LIST_IMPLEMENTATION_HPP
-#define ACTS_ACTION_LIST_IMPLEMENTATION_HPP
-
+#pragma once
 #include "Acts/Utilities/detail/MPL/type_collector.hpp"
 
 namespace Acts {
@@ -81,6 +79,4 @@ namespace detail {
   };
 
 }  // namespace detail
-}  // namespace Acts
-
-#endif  // ACTS_ACTION_LIST_IMPLEMENTATION_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Propagator/detail/action_signature_check.hpp b/Core/include/Acts/Propagator/detail/action_signature_check.hpp
index 00d317cb7f3023f99f280ae13c85b61e28cb05f6..276d4062af28195666ced9d690d4e9025d4c398b 100644
--- a/Core/include/Acts/Propagator/detail/action_signature_check.hpp
+++ b/Core/include/Acts/Propagator/detail/action_signature_check.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_ACTION_SIGNATURE_CHECK_HPP
-#define ACTS_ACTION_SIGNATURE_CHECK_HPP
-
+#pragma once
 #include <type_traits>
 #include "Acts/Utilities/detail/MPL/type_collector.hpp"
 
@@ -66,5 +64,4 @@ namespace detail {
       = action_signature_check<T, cache_t>::value;
 }  // namespace detail
 
-}  // namespace Acts
-#endif  // ACTS_OBSERVER_SIGNATURE_CHECK_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Propagator/detail/condition_uses_result_type.hpp b/Core/include/Acts/Propagator/detail/condition_uses_result_type.hpp
index 791699364e1d155f2c14e1da71f8fe39fdd0d8df..24fda6a41615b3deefb13dfbca843f91a5815d8f 100644
--- a/Core/include/Acts/Propagator/detail/condition_uses_result_type.hpp
+++ b/Core/include/Acts/Propagator/detail/condition_uses_result_type.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_CONDITION_USES_RESULT_TYPE_HPP
-#define ACTS_CONDITION_USES_RESULT_TYPE_HPP 1
-
+#pragma once
 #include <type_traits>
 #include "Acts/Utilities/detail/MPL/type_collector.hpp"
 
@@ -35,5 +33,4 @@ namespace detail {
 
 }  // namespace detail
 
-}  // namespace Acts
-#endif  // ACTS_CONDITION_USES_RESULT_TYPE_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Propagator/detail/standard_abort_conditions.hpp b/Core/include/Acts/Propagator/detail/standard_abort_conditions.hpp
index 2455e0fd0c02b28f537f85f042a9061c33abb559..945f5313d5ab8d2eb74ca8e18bb73de3b91f0d76 100644
--- a/Core/include/Acts/Propagator/detail/standard_abort_conditions.hpp
+++ b/Core/include/Acts/Propagator/detail/standard_abort_conditions.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_STANDARD_ABORT_CONDITIONS_HPP
-#define ACTS_STANDARD_ABORT_CONDITIONS_HPP
-
+#pragma once
 #include <limits>
 
 namespace Acts {
@@ -121,6 +119,4 @@ namespace detail {
   };
 
 }  // namespace detail
-}  // namespace Acts
-
-#endif
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Seeding/BarrelSeedFinder.hpp b/Core/include/Acts/Seeding/BarrelSeedFinder.hpp
index 4f0de62a0fb6b05f850f823f462b9fd1bb912dd9..2339ef83fef5c6f5385a2a27f32f98d9b242bc36 100644
--- a/Core/include/Acts/Seeding/BarrelSeedFinder.hpp
+++ b/Core/include/Acts/Seeding/BarrelSeedFinder.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_SEEDING_BARRELSEEDFINDER_HPP
-#define ACTS_SEEDING_BARRELSEEDFINDER_HPP
-
+#pragma once
 #include "Acts/Seeding/SpacePoint.hpp"
 #include "Acts/Seeding/TrackSeed.hpp"
 #include "Acts/Seeding/detail/geometry.hpp"
@@ -65,6 +63,4 @@ Acts::Seeding::findHelixSeeds(const HelixSeedConfig&               cfg,
       }
     }
   }
-}
-
-#endif  // ACTS_SEEDING_BARRELSEEDFINDER_HPP
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Seeding/SpacePoint.hpp b/Core/include/Acts/Seeding/SpacePoint.hpp
index 9e2f4ebcae2781344afb61cd143e31ba537b25c8..9c0c3a31869d8c62faee91ede34dce2a26345ba8 100644
--- a/Core/include/Acts/Seeding/SpacePoint.hpp
+++ b/Core/include/Acts/Seeding/SpacePoint.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_SEEDING_SPACEPOINT_HPP
-#define ACTS_SEEDING_SPACEPOINT_HPP
-
+#pragma once
 #include <algorithm>
 #include <ostream>
 #include <vector>
@@ -115,6 +113,4 @@ namespace Seeding {
   }
 
 }  // namespace Seeding
-}  // namespace Acts
-
-#endif  // ACTS_SEEDING_SPACEPOINT_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Seeding/TrackSeed.hpp b/Core/include/Acts/Seeding/TrackSeed.hpp
index 591c74a08e6fce062803f7f204e20ead3bae1265..5bf6c841d69f8ba6baa09ce73119faae13582d98 100644
--- a/Core/include/Acts/Seeding/TrackSeed.hpp
+++ b/Core/include/Acts/Seeding/TrackSeed.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_SEEDING_TRACKSEED_HPP
-#define ACTS_SEEDING_TRACKSEED_HPP
-
+#pragma once
 #include <array>
 #include <ostream>
 #include <utility>
@@ -101,6 +99,4 @@ namespace Seeding {
   using TrackSeeds4 = TrackSeeds<Identifier, 4>;
 
 }  // namespace Seeding
-}  // namespace Acts
-
-#endif  // ACTS_SEEDING_TRACKSEED_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Seeding/detail/cyclic_range.hpp b/Core/include/Acts/Seeding/detail/cyclic_range.hpp
index 117a50a6f63b60f5b5432455f405a1187e820fd0..1d95da97df94b4fb24d9643fbf298a454fd841e4 100644
--- a/Core/include/Acts/Seeding/detail/cyclic_range.hpp
+++ b/Core/include/Acts/Seeding/detail/cyclic_range.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_SEEDING_RANGE_HPP
-#define ACTS_SEEDING_RANGE_HPP
-
+#pragma once
 #include <algorithm>
 
 #include "Acts/Utilities/detail/periodic.hpp"
@@ -127,6 +125,4 @@ namespace detail {
   }
 
 }  // namespace detail
-}  // namespace Acts
-
-#endif  // ACTS_SEEDING_RANGE_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Seeding/detail/geometry.hpp b/Core/include/Acts/Seeding/detail/geometry.hpp
index c795b5e16825f7876c8f0939dfcc9f4ce7652a6a..79408e0832bacbcabba15bdd70efe23a012b4e46 100644
--- a/Core/include/Acts/Seeding/detail/geometry.hpp
+++ b/Core/include/Acts/Seeding/detail/geometry.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_SEEDING_GEOMETRY_HPP
-#define ACTS_SEEDING_GEOMETRY_HPP
-
+#pragma once
 #include <cmath>
 
 #include "Acts/Utilities/Definitions.hpp"
@@ -122,6 +120,4 @@ namespace detail {
   }
 
 }  // namespace detail
-}  // namespace Acts
-
-#endif  // ACTS_SEEDING_GEOMETRY_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/BoundaryCheck.hpp b/Core/include/Acts/Surfaces/BoundaryCheck.hpp
index 8767f9fcc072230daaf6d3ebd78e5d0f9460a024..9e18d1122fba79da8807cef5a01a6506ca17948b 100644
--- a/Core/include/Acts/Surfaces/BoundaryCheck.hpp
+++ b/Core/include/Acts/Surfaces/BoundaryCheck.hpp
@@ -10,9 +10,7 @@
 // BoundaryCheck.hpp, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_BOUNDARYCHECK_H
-#define ACTS_SURFACES_BOUNDARYCHECK_H
-
+#pragma once
 #include <cfloat>
 #include <cmath>
 #include <iterator>
@@ -368,6 +366,4 @@ Acts::BoundaryCheck::computeClosestPointOnPolygon(
     closest = last;
   }
   return closest;
-}
-
-#endif  // ACTS_SURFACES_BOUNDARYCHECK_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/ConeBounds.hpp b/Core/include/Acts/Surfaces/ConeBounds.hpp
index a71fccc55e3fd86cdc0499606c2198c10c6fdd68..c059018cb3616a2d68a335afe50eaffdcd580327 100644
--- a/Core/include/Acts/Surfaces/ConeBounds.hpp
+++ b/Core/include/Acts/Surfaces/ConeBounds.hpp
@@ -10,9 +10,7 @@
 // ConeBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACESCONEBOUNDS_H
-#define ACTS_SURFACESCONEBOUNDS_H
-
+#pragma once
 #include <cfloat>
 
 #include "Acts/Surfaces/SurfaceBounds.hpp"
@@ -220,6 +218,4 @@ ConeBounds::halfPhiSector() const
 {
   return m_halfPhi;
 }
-}
-
-#endif  // ACTS_SURFACESCONEBOUNDS_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/ConeSurface.hpp b/Core/include/Acts/Surfaces/ConeSurface.hpp
index 61d294a5d6178da1d0b719556205dfabcccb32a4..7a1d00a8c8806e29840f68e9f047c9d813c7e0fc 100644
--- a/Core/include/Acts/Surfaces/ConeSurface.hpp
+++ b/Core/include/Acts/Surfaces/ConeSurface.hpp
@@ -10,9 +10,7 @@
 // ConeSurface.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_CONESURFACE_H
-#define ACTS_SURFACES_CONESURFACE_H 1
-
+#pragma once
 #include "Acts/Surfaces/ConeBounds.hpp"
 #include "Acts/Surfaces/Surface.hpp"
 #include "Acts/Utilities/Definitions.hpp"
@@ -236,6 +234,4 @@ protected:
   std::shared_ptr<const ConeBounds> m_bounds;  ///< bounds (shared)
 };
 
-}  // end of namespace
-
-#endif  // ACTS_SURFACESCONESURFACE_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/CylinderBounds.hpp b/Core/include/Acts/Surfaces/CylinderBounds.hpp
index a6f0c0576ed25d4c110a4117f805fef5ab1e9805..8f4497e6a371ca48f6051a271a1e40ac9b654e6a 100644
--- a/Core/include/Acts/Surfaces/CylinderBounds.hpp
+++ b/Core/include/Acts/Surfaces/CylinderBounds.hpp
@@ -10,9 +10,7 @@
 // CylinderBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_CYLINDERBOUNDS_H
-#define ACTS_SURFACES_CYLINDERBOUNDS_H 1
-
+#pragma once
 #include <cmath>
 
 #include "Acts/Surfaces/SurfaceBounds.hpp"
@@ -178,6 +176,4 @@ CylinderBounds::halflengthZ() const
 {
   return m_halfZ;
 }
-}
-
-#endif  // ACTS_SURFACES_CYLINDERBOUNDS_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/CylinderSurface.hpp b/Core/include/Acts/Surfaces/CylinderSurface.hpp
index 0e22e00f203b9206b00934f467fd350a30a1e05b..d3be2e3a5148e606dda087b2b974d59e329fee9c 100644
--- a/Core/include/Acts/Surfaces/CylinderSurface.hpp
+++ b/Core/include/Acts/Surfaces/CylinderSurface.hpp
@@ -10,9 +10,7 @@
 // CylinderSurface.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_CYLINDERSURFACE_H
-#define ACTS_SURFACES_CYLINDERSURFACE_H 1
-
+#pragma once
 #include <cmath>
 
 #include "Acts/Surfaces/CylinderBounds.hpp"
@@ -259,6 +257,4 @@ CylinderSurface::rotSymmetryAxis() const
   return transform().matrix().block<3, 1>(0, 2);
 }
 
-}  // end of namespace
-
-#endif  // ACTS_SURFACES_CYLINDERSURFACE_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/DiamondBounds.hpp b/Core/include/Acts/Surfaces/DiamondBounds.hpp
index 47424df464d316001b6e6f6341e42d673d0e3e71..610631dadc5d1af93201c33b671ff76d1029c33f 100644
--- a/Core/include/Acts/Surfaces/DiamondBounds.hpp
+++ b/Core/include/Acts/Surfaces/DiamondBounds.hpp
@@ -10,9 +10,7 @@
 // DiamondBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_DIAMONDDBOUNDS_H
-#define ACTS_SURFACES_DIAMONDDBOUNDS_H 1
-
+#pragma once
 #include <cmath>
 
 #include "Acts/Surfaces/PlanarBounds.hpp"
@@ -166,6 +164,4 @@ DiamondBounds::halflengthY2() const
   return m_maxY;
 }
 
-}  // end of namespace
-
-#endif  // ACTS_SURFACES_DIAMONDBOUNDS_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/DiscBounds.hpp b/Core/include/Acts/Surfaces/DiscBounds.hpp
index 5b8d4683d4110c2cc3041913750b83e5eb5a66b3..ee1aaddf739984cc4ef3ab8d50ae9b785d66ce62 100644
--- a/Core/include/Acts/Surfaces/DiscBounds.hpp
+++ b/Core/include/Acts/Surfaces/DiscBounds.hpp
@@ -10,9 +10,7 @@
 // DiscBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACESDISCBOUNDS_H
-#define ACTS_SURFACESDISCBOUNDS_H
-
+#pragma once
 #include "Acts/Surfaces/SurfaceBounds.hpp"
 
 namespace Acts {
@@ -26,6 +24,4 @@ class DiscBounds : public SurfaceBounds
 {
 };
 
-}  // end of namespace
-
-#endif  // ACTS_SURFACESDISCBOUNDS_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/DiscSurface.hpp b/Core/include/Acts/Surfaces/DiscSurface.hpp
index d02ed245f22cde51f69858e6c7bbc837dcd79ebb..2fad108451e011ea831ae89ec81604631469cca9 100644
--- a/Core/include/Acts/Surfaces/DiscSurface.hpp
+++ b/Core/include/Acts/Surfaces/DiscSurface.hpp
@@ -10,9 +10,7 @@
 // DiscSurface.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACE_SDISCSURFACE_H
-#define ACTS_SURFACE_SDISCSURFACE_H 1
-
+#pragma once
 #include "Acts/Surfaces/DiscBounds.hpp"
 #include "Acts/Surfaces/InfiniteBounds.hpp"
 #include "Acts/Surfaces/Surface.hpp"
@@ -420,6 +418,4 @@ inline const RotationMatrix3D
   return rframeT;
 }
 
-}  // end of namespace
-
-#endif  // ACTS_SURFACES_DISCSURFACE_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/DiscTrapezoidalBounds.hpp b/Core/include/Acts/Surfaces/DiscTrapezoidalBounds.hpp
index 5c0d978dfe439747c1a5c08fc8bbb4fe83d23bf5..acf2df77e0322a69cb6e82f043461db59f8c1d61 100644
--- a/Core/include/Acts/Surfaces/DiscTrapezoidalBounds.hpp
+++ b/Core/include/Acts/Surfaces/DiscTrapezoidalBounds.hpp
@@ -10,9 +10,7 @@
 // DiscTrapezoidalBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_DISCTRAPEZOIDALBOUNDS_H
-#define ACTS_SURFACES_DISCTRAPEZOIDALBOUNDS_H
-
+#pragma once
 #include <cmath>
 
 #include "Acts/Surfaces/DiscBounds.hpp"
@@ -208,6 +206,4 @@ DiscTrapezoidalBounds::halflengthY() const
   return (hmax - hmin) / 2.0;
 }
 
-}  // namespace Acts
-
-#endif  // ACTS_SURFACES_DISCTRAPEZOIDALBOUNDS_H
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/EllipseBounds.hpp b/Core/include/Acts/Surfaces/EllipseBounds.hpp
index e3b4003c6a7181c3d10b739ce60c95b2c720a2cf..2dd53d7c39e32de3f628c6e6546f3a8052315405 100644
--- a/Core/include/Acts/Surfaces/EllipseBounds.hpp
+++ b/Core/include/Acts/Surfaces/EllipseBounds.hpp
@@ -10,9 +10,7 @@
 // EllipseBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_ELLIPSEBOUNDS_H
-#define ACTS_SURFACES_ELLIPSEBOUNDS_H 1
-
+#pragma once
 #include <cmath>
 #include <cstdlib>
 
@@ -179,6 +177,4 @@ EllipseBounds::halfPhiSector() const
   return m_halfPhi;
 }
 
-}  // end of namespace
-
-#endif  // ACTS_SURFACES_ELLIPSEBOUNDS_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/InfiniteBounds.hpp b/Core/include/Acts/Surfaces/InfiniteBounds.hpp
index d6333051a11c906d25a46f31af203538f9c564c4..3ea1687369aa9c495559f3949af1fd17b377033d 100644
--- a/Core/include/Acts/Surfaces/InfiniteBounds.hpp
+++ b/Core/include/Acts/Surfaces/InfiniteBounds.hpp
@@ -10,9 +10,7 @@
 // InfiniteBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_INFINITE_BOUNDS_H
-#define ACTS_INFINITE_BOUNDS_H 1
-
+#pragma once
 #include "Acts/Surfaces/SurfaceBounds.hpp"
 #include "Acts/Utilities/Definitions.hpp"
 #include "Acts/Utilities/VariantDataFwd.hpp"
@@ -84,6 +82,4 @@ public:
 
 static const InfiniteBounds s_noBounds{};
 
-}  // namespace Acts
-
-#endif  // ACTS_INFINITE_BOUNDS_H
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/LineBounds.hpp b/Core/include/Acts/Surfaces/LineBounds.hpp
index a1e1e8c5c087703adefe535d48de807d62b8fbf8..e1d94a59bd4b2358e3ba8cf29741133f17ddf717 100644
--- a/Core/include/Acts/Surfaces/LineBounds.hpp
+++ b/Core/include/Acts/Surfaces/LineBounds.hpp
@@ -10,9 +10,7 @@
 // LineBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_LINEBOUNDS_H
-#define ACTS_SURFACES_LINEBOUNDS_H 1
-
+#pragma once
 #include "Acts/Surfaces/SurfaceBounds.hpp"
 #include "Acts/Utilities/Definitions.hpp"
 #include "Acts/Utilities/VariantDataFwd.hpp"
@@ -108,6 +106,4 @@ LineBounds::halflengthZ() const
   return m_halfZ;
 }
 
-}  // end of namespace
-
-#endif  // ACTS_SURFACES_LINEBOUNDS_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/LineSurface.hpp b/Core/include/Acts/Surfaces/LineSurface.hpp
index 0e2ae3eb77d622b8f7e9ff932e13a3e0f32cd0d2..d7e3a2f535d5a93084a195f0ed8e797348ebe4df 100644
--- a/Core/include/Acts/Surfaces/LineSurface.hpp
+++ b/Core/include/Acts/Surfaces/LineSurface.hpp
@@ -10,9 +10,7 @@
 // LineSurface.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_LINESURFACE_H
-#define ACTS_SURFACES_LINESURFACE_H
-
+#pragma once
 #include "Acts/Surfaces/InfiniteBounds.hpp"
 #include "Acts/Surfaces/LineBounds.hpp"
 #include "Acts/Surfaces/Surface.hpp"
@@ -383,6 +381,4 @@ LineSurface::derivativeFactors(const Vector3D&         pos,
       * (s_vec - pc * (long_mat * d_vec.asDiagonal() - jac.block<3, 5>(3, 0))));
 }
 
-}  // end of namespace
-
-#endif  // ACTS_SURFACES_LINESURFACE_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/PerigeeSurface.hpp b/Core/include/Acts/Surfaces/PerigeeSurface.hpp
index 981ee380e8aea38c3cc3aa32560f760c85d7637b..84d6c51037757c39295b84dcffcf30c90ef1f936 100644
--- a/Core/include/Acts/Surfaces/PerigeeSurface.hpp
+++ b/Core/include/Acts/Surfaces/PerigeeSurface.hpp
@@ -10,9 +10,7 @@
 // PerigeeSurface.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_PERIGEESURFACE_H
-#define ACTS_SURFACES_PERIGEESURFACE_H 1
-
+#pragma once
 #include "Acts/Surfaces/InfiniteBounds.hpp"
 #include "Acts/Surfaces/LineSurface.hpp"
 #include "Acts/Utilities/Definitions.hpp"
@@ -93,6 +91,4 @@ public:
   toVariantData() const override;
 };
 
-}  // end of namespace
-
-#endif  // ACTS_SURFACESPERIGEESURFACE_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/PlanarBounds.hpp b/Core/include/Acts/Surfaces/PlanarBounds.hpp
index 0447ae0f30f72a5f4c4f1ca6f09b93446c2a30d2..c10b041b21c889c183e5f71a680f53772a179011 100644
--- a/Core/include/Acts/Surfaces/PlanarBounds.hpp
+++ b/Core/include/Acts/Surfaces/PlanarBounds.hpp
@@ -10,9 +10,7 @@
 // PlanarBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_PLANARBOUNDS_H
-#define ACTS_SURFACES_PLANARBOUNDS_H 1
-
+#pragma once
 #include <vector>
 
 #include "Acts/Surfaces/SurfaceBounds.hpp"
@@ -46,6 +44,4 @@ public:
   toVariantData() const = 0;
 };
 
-}  // end of namespace
-
-#endif  // ACTS_SURFACES_PLANARBOUNDS_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/PlaneSurface.hpp b/Core/include/Acts/Surfaces/PlaneSurface.hpp
index 4dc117f372aa911078a33bab9812b53c57c34aed..de665ef7eacae6f16bb11d8b98588bfa92d99a72 100644
--- a/Core/include/Acts/Surfaces/PlaneSurface.hpp
+++ b/Core/include/Acts/Surfaces/PlaneSurface.hpp
@@ -10,9 +10,7 @@
 // PlaneSurface.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_PLANESURFACE_H
-#define ACTS_SURFACES_PLANESURFACE_H 1
-
+#pragma once
 #include <limits>
 #include "Acts/Surfaces/InfiniteBounds.hpp"
 #include "Acts/Surfaces/PlanarBounds.hpp"
@@ -241,6 +239,4 @@ PlaneSurface::intersectionEstimate(const Vector3D&      gpos,
   return Intersection(gpos, std::numeric_limits<double>::max(), false);
 }
 
-}  // end of namespace
-
-#endif  // ACTS_SURFACES_PLANESURFACE_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/RadialBounds.hpp b/Core/include/Acts/Surfaces/RadialBounds.hpp
index f9a209b922a67e041a1461b7945aef6066dda6f7..e5a6b3583593d73eacb82a5acdebaa57bab6dd24 100644
--- a/Core/include/Acts/Surfaces/RadialBounds.hpp
+++ b/Core/include/Acts/Surfaces/RadialBounds.hpp
@@ -10,9 +10,7 @@
 // RadialBounds.h, c) ATLAS Detector software
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_RADIALBOUNDS_H
-#define ACTS_SURFACES_RADIALBOUNDS_H 1
-
+#pragma once
 #include <cmath>
 
 #include "Acts/Surfaces/DiscBounds.hpp"
@@ -155,6 +153,4 @@ RadialBounds::halfPhiSector() const
   return m_halfPhi;
 }
 
-}  // end of namespace
-
-#endif  // ACTS_SURFACES_RADIALBOUNDS_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/RectangleBounds.hpp b/Core/include/Acts/Surfaces/RectangleBounds.hpp
index 7b0803e87ad78f6c2ac078544ac95e7775824327..01e3f8b25b43f7a69fed3430f87abccfca2d1dc1 100644
--- a/Core/include/Acts/Surfaces/RectangleBounds.hpp
+++ b/Core/include/Acts/Surfaces/RectangleBounds.hpp
@@ -10,9 +10,7 @@
 // RectangleBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_RECTANGLEBOUNDS_H
-#define ACTS_SURFACES_RECTANGLEBOUNDS_H 1
-
+#pragma once
 #include "Acts/Surfaces/PlanarBounds.hpp"
 #include "Acts/Utilities/Definitions.hpp"
 #include "Acts/Utilities/VariantDataFwd.hpp"
@@ -126,6 +124,4 @@ RectangleBounds::type() const
   return SurfaceBounds::Rectangle;
 }
 
-}  // end of namespace
-
-#endif  // ACTS_SURFACES_RECTANGLEBOUNDS_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/StrawSurface.hpp b/Core/include/Acts/Surfaces/StrawSurface.hpp
index 2c6579e790a33bf5349f77878d0bb8d295a65549..a58be5195a4567f68cb690c3e1f3efecce3f22b2 100644
--- a/Core/include/Acts/Surfaces/StrawSurface.hpp
+++ b/Core/include/Acts/Surfaces/StrawSurface.hpp
@@ -10,9 +10,7 @@
 // StrawSurface.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_STRAWSURFACE_H
-#define ACTS_SURFACES_STRAWSURFACE_H
-
+#pragma once
 #include "Acts/Surfaces/LineBounds.hpp"
 #include "Acts/Surfaces/LineSurface.hpp"
 #include "Acts/Utilities/Definitions.hpp"
@@ -120,6 +118,4 @@ Acts::StrawSurface::name() const
   return "Acts::StrawSurface";
 }
 
-}  // end of namespace
-
-#endif  // ACTS_SURFACESSTRAIGHTLINESURFACE_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/Surface.hpp b/Core/include/Acts/Surfaces/Surface.hpp
index dc6bfaa96add369bd758b69bd0995092c6712feb..aba9a9d5a69353a69fd4d52904c33ed4236ea8f2 100644
--- a/Core/include/Acts/Surfaces/Surface.hpp
+++ b/Core/include/Acts/Surfaces/Surface.hpp
@@ -10,9 +10,7 @@
 // Surface.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_SURFACE_H
-#define ACTS_SURFACES_SURFACE_H 1
-
+#pragma once
 #include "Acts/Detector/DetectorElementBase.hpp"
 #include "Acts/Surfaces/BoundaryCheck.hpp"
 #include "Acts/Surfaces/SurfaceBounds.hpp"
@@ -557,6 +555,4 @@ Surface::associateLayer(const Layer& lay)
 std::ostream&
 operator<<(std::ostream& sl, const Surface& sf);
 
-}  // end of namespace Acts
-
-#endif  // ACTS_SURFACES_SURFACE_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/SurfaceArray.hpp b/Core/include/Acts/Surfaces/SurfaceArray.hpp
index 499902f0b62116e4b9e63f0be0cd8921a90cc6dd..54e82284ca6d8f82c819aee6566d1ecb821bbe81 100644
--- a/Core/include/Acts/Surfaces/SurfaceArray.hpp
+++ b/Core/include/Acts/Surfaces/SurfaceArray.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_SURFACES_SURFACEARRAY_H
-#define ACTS_SURFACES_SURFACEARRAY_H
-
+#pragma once
 #include <iostream>
 #include <type_traits>
 #include <vector>
@@ -706,6 +704,4 @@ private:
   surfaceGridLookupToVariantData(const ISurfaceGridLookup& sgl) const;
 };
 
-}  // namespace Acts
-
-#endif  // ACTS_SURFACES_SURFACEARRAY_H
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/SurfaceBounds.hpp b/Core/include/Acts/Surfaces/SurfaceBounds.hpp
index 79ac27e6372348a4bd1c79638da8f996fcec8f38..bbaedff4bf65dc63525b4ab756bc240e157fca50 100644
--- a/Core/include/Acts/Surfaces/SurfaceBounds.hpp
+++ b/Core/include/Acts/Surfaces/SurfaceBounds.hpp
@@ -10,9 +10,7 @@
 // SurfaceBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_SURFACEBOUNDS_H
-#define ACTS_SURFACES_SURFACEBOUNDS_H
-
+#pragma once
 #include <ostream>
 
 #include "Acts/Surfaces/BoundaryCheck.hpp"
@@ -123,6 +121,4 @@ operator<<(std::ostream& os, const SurfaceBounds& sb)
   return sb.dump(os);
 }
 
-}  // namespace Acts
-
-#endif  // ACTS_SURFACES_SURFACEBOUNDS_H
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/TrapezoidBounds.hpp b/Core/include/Acts/Surfaces/TrapezoidBounds.hpp
index ce871ae5634f3c96b26e3e94aa47adeb4e1a4466..7b986fdf92442d611bf1fdb968b1f70e99b7bffd 100644
--- a/Core/include/Acts/Surfaces/TrapezoidBounds.hpp
+++ b/Core/include/Acts/Surfaces/TrapezoidBounds.hpp
@@ -10,9 +10,7 @@
 // TrapezoidBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_TRAPEZOIDBOUNDS_H
-#define ACTS_SURFACES_TRAPEZOIDBOUNDS_H 1
-
+#pragma once
 #include <cmath>
 
 #include "Acts/Surfaces/PlanarBounds.hpp"
@@ -182,6 +180,4 @@ TrapezoidBounds::halflengthY() const
   return m_halfY;
 }
 
-}  // end of namespace
-
-#endif  // ACTS_SURFACES_TRAPEZOIDBOUNDS_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Surfaces/TriangleBounds.hpp b/Core/include/Acts/Surfaces/TriangleBounds.hpp
index b9fe7c9648be5fd22aee69f560e3d433bdc42711..8e61913b1d77a53a66540baae18e7a94ca83a892 100644
--- a/Core/include/Acts/Surfaces/TriangleBounds.hpp
+++ b/Core/include/Acts/Surfaces/TriangleBounds.hpp
@@ -10,9 +10,7 @@
 // TriangleBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACESTRIANGLEBOUNDS_H
-#define ACTS_SURFACESTRIANGLEBOUNDS_H
-
+#pragma once
 #include <array>
 #include <utility>
 
@@ -108,6 +106,4 @@ private:
   RectangleBounds m_boundingBox;  ///< internal bounding box cache
 };
 
-}  // end of namespace
-
-#endif  // ACTS_SURFACESRECTANGLEBOUNDS_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Tools/CylinderVolumeBuilder.hpp b/Core/include/Acts/Tools/CylinderVolumeBuilder.hpp
index 70e3113a9b54fcf0738a4eeb4b610436258106fa..4eb7f989a32895e47a45796a300e4ccc1bb11a8f 100644
--- a/Core/include/Acts/Tools/CylinderVolumeBuilder.hpp
+++ b/Core/include/Acts/Tools/CylinderVolumeBuilder.hpp
@@ -10,9 +10,7 @@
 // CylinderVolumeBuilder.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_TOOLS_CYLINDERVOLUMEBUILDER_H
-#define ACTS_TOOLS_CYLINDERVOLUMEBUILDER_H
-
+#pragma once
 #include <limits>
 #include <string>
 #include "Acts/Material/Material.hpp"
@@ -597,6 +595,4 @@ CylinderVolumeBuilder::getConfiguration() const
   return m_cfg;
 }
 
-}  // end of namespace
-
-#endif  // ACTS_TOOLS_CYLINDERVOLUMEBUILDER_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Tools/CylinderVolumeHelper.hpp b/Core/include/Acts/Tools/CylinderVolumeHelper.hpp
index 58d8796f9cb3d8930a25aca5c7ebba32179334ea..54e090b0ffd48cef441eb6405ae3a6ba80821f6d 100644
--- a/Core/include/Acts/Tools/CylinderVolumeHelper.hpp
+++ b/Core/include/Acts/Tools/CylinderVolumeHelper.hpp
@@ -10,9 +10,7 @@
 // CylinderVolumeHelper.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_TOOLS_CYLINDERVOLUMEHELPER_H
-#define ACTS_TOOLS_CYLINDERVOLUMEHELPER_H 1
-
+#pragma once
 #ifndef ACTS_TOOLS_TAKESMALLERBIGGER
 #define ACTS_TOOLS_TAKESMALLERBIGGER
 #define takeSmaller(current, test) current = current < test ? current : test
@@ -319,6 +317,4 @@ CylinderVolumeHelper::getConfiguration() const
 {
   return m_cfg;
 }
-}
-
-#endif  // ACTS_TOOLS_CYLINDERVOLUMEHELPER_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Tools/ILayerArrayCreator.hpp b/Core/include/Acts/Tools/ILayerArrayCreator.hpp
index 2544a49ed6c0a54ff2c826018fd930cd2651ea76..1e9e33c3daed6f9bae3a0e8ba2ca289d82db541b 100644
--- a/Core/include/Acts/Tools/ILayerArrayCreator.hpp
+++ b/Core/include/Acts/Tools/ILayerArrayCreator.hpp
@@ -10,9 +10,7 @@
 // ILayerArrayCreator.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_TOOLS_ILAYERARRAYCREATOR_H
-#define ACTS_TOOLS_ILAYERARRAYCREATOR_H 1
-
+#pragma once
 #include <memory>
 #include <vector>
 #include "Acts/Utilities/BinnedArray.hpp"
@@ -57,6 +55,4 @@ public:
              BinningType        btype  = arbitrary,
              BinningValue       bvalue = binX) const = 0;
 };
-}  // end of namespace
-
-#endif  // ACTS_TOOLS_ILAYERARRAYCREATOR_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Tools/ILayerBuilder.hpp b/Core/include/Acts/Tools/ILayerBuilder.hpp
index 60f0c5f23864501574dec644f085fac3e21a5443..d2079460209b8b50b9941e02685e21039788bd6d 100644
--- a/Core/include/Acts/Tools/ILayerBuilder.hpp
+++ b/Core/include/Acts/Tools/ILayerBuilder.hpp
@@ -10,9 +10,7 @@
 // ILayerBuilder.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_TOOLS_ILAYERBUILDER_H
-#define ACTS_TOOLS_ILAYERBUILDER_H 1
-
+#pragma once
 #include <memory>
 #include <string>
 #include <vector>
@@ -55,6 +53,4 @@ public:
   identification() const = 0;
 };
 
-}  // end of namespace
-
-#endif  // ACTS_TOOLS_ILAYERBUILDER_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Tools/ITrackingGeometryBuilder.hpp b/Core/include/Acts/Tools/ITrackingGeometryBuilder.hpp
index daa7aabe1e8684431e366bf6644549820156e8b8..e679e9d2163fab3b088b2d69e2783b52be3ccca4 100644
--- a/Core/include/Acts/Tools/ITrackingGeometryBuilder.hpp
+++ b/Core/include/Acts/Tools/ITrackingGeometryBuilder.hpp
@@ -10,9 +10,7 @@
 // ITrackingGeometryBuilder.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_GEOMETRYINTERFACES_ITRACKINGGEOMETRYBUILDER_H
-#define ACTS_GEOMETRYINTERFACES_ITRACKINGGEOMETRYBUILDER_H 1
-
+#pragma once
 #include <memory>
 
 namespace Acts {
@@ -40,6 +38,4 @@ public:
   virtual std::unique_ptr<const TrackingGeometry>
   trackingGeometry() const = 0;
 };
-}  // end of namespace
-
-#endif  // ACTS_GEOMETRYINTERFACES_IGEOMETRYBUILDER_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Tools/ITrackingVolumeArrayCreator.hpp b/Core/include/Acts/Tools/ITrackingVolumeArrayCreator.hpp
index 3b1db9cb537d333792863f6731e4d3c276f3201a..55a68975cf1d6cce4300a3bfcb6dfbfa64368df8 100644
--- a/Core/include/Acts/Tools/ITrackingVolumeArrayCreator.hpp
+++ b/Core/include/Acts/Tools/ITrackingVolumeArrayCreator.hpp
@@ -10,9 +10,7 @@
 // ITrackingVolumeArrayCreator.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_GEOMETRYINTERFACES_ITRACKINGVOLUMEARRAYCREATOR_H
-#define ACTS_GEOMETRYINTERFACES_ITRACKINGVOLUMEARRAYCREATOR_H 1
-
+#pragma once
 #include <memory>
 #include <vector>
 #include "Acts/Utilities/BinnedArray.hpp"
@@ -60,6 +58,4 @@ public:
   trackingVolumeArray(const TrackingVolumeVector& vols,
                       BinningValue                bVal) const = 0;
 };
-}  // end of namespace
-
-#endif
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Tools/ITrackingVolumeBuilder.hpp b/Core/include/Acts/Tools/ITrackingVolumeBuilder.hpp
index 6941f30e86cf8fa8bfdb983e323adcab3c5f7f82..dbe61f5d2437167ff84569d893790ee0f7cc0707 100644
--- a/Core/include/Acts/Tools/ITrackingVolumeBuilder.hpp
+++ b/Core/include/Acts/Tools/ITrackingVolumeBuilder.hpp
@@ -10,9 +10,7 @@
 // ITrackingVolumeBuilder.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_TOOLS_ITRACKINGVOLUMEBUILDER_H
-#define ACTS_TOOLS_ITRACKINGVOLUMEBUILDER_H 1
-
+#pragma once
 #include <memory>
 #include <tuple>
 #include <vector>
@@ -57,6 +55,4 @@ public:
                  VolumeBoundsPtr   outsideBounds = nullptr) const = 0;
 };
 
-}  // end of namespace
-
-#endif  // ACTS_TOOLS_ITRACKINGVOLUMEBUILDER_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Tools/ITrackingVolumeHelper.hpp b/Core/include/Acts/Tools/ITrackingVolumeHelper.hpp
index 3c63e95447eb4e76db32cc279ae4dcab1790d765..734e7706df58037dd43d4215006f6dcd7918a605 100644
--- a/Core/include/Acts/Tools/ITrackingVolumeHelper.hpp
+++ b/Core/include/Acts/Tools/ITrackingVolumeHelper.hpp
@@ -10,9 +10,7 @@
 // ITrackingVolumeHelper.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_TOOLS_ITRACKINGVOLUMEHELPER_H
-#define ACTS_TOOLS_ITRACKINGVOLUMEHELPER_H 1
-
+#pragma once
 // Geometry module
 #include "Acts/Utilities/BinningType.hpp"
 // Core module
@@ -147,6 +145,4 @@ public:
   createContainerTrackingVolume(const TrackingVolumeVector& volumes) const = 0;
 };
 
-}  // end of namespace
-
-#endif  // ACTS_TOOLS_ITRACKINGVOLUMEHELPER_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Tools/LayerArrayCreator.hpp b/Core/include/Acts/Tools/LayerArrayCreator.hpp
index 04c076eb058d4e2e2103a47e3f71dc36470ffbc2..eb40242ac065c516d3cf1e1422cd3c12446e11e7 100644
--- a/Core/include/Acts/Tools/LayerArrayCreator.hpp
+++ b/Core/include/Acts/Tools/LayerArrayCreator.hpp
@@ -10,9 +10,7 @@
 // LayerArrayCreator.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_TOOLS_LAYERARRAYCREATOR_H
-#define ACTS_TOOLS_LAYERARRAYCREATOR_H 1
-
+#pragma once
 #ifndef ACTS_TOOLS_TAKESMALLERBIGGER
 #define ACTS_TOOLS_TAKESMALLERBIGGER
 #define takeSmaller(current, test) current = current < test ? current : test
@@ -99,6 +97,4 @@ private:
                           double       offset) const;
 };
 
-}  // end of namespace
-
-#endif  // ACTS_GEOMETRYTOOLS_LAYERARRAYCREATOR_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Tools/LayerCreator.hpp b/Core/include/Acts/Tools/LayerCreator.hpp
index 9e9af3f589b35f49140235bbe65e4c0f35058aa8..1c7fbbd24d0cd3b5059f29485d2946cdf600b23a 100644
--- a/Core/include/Acts/Tools/LayerCreator.hpp
+++ b/Core/include/Acts/Tools/LayerCreator.hpp
@@ -10,9 +10,7 @@
 // LayerCreator.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_GEOMETRYTOOLS_LAYERCREATOR_H
-#define ACTS_GEOMETRYTOOLS_LAYERCREATOR_H 1
-
+#pragma once
 #include <boost/optional.hpp>
 #include "Acts/Tools/SurfaceArrayCreator.hpp"
 #include "Acts/Utilities/ApproachDescriptor.hpp"
@@ -241,6 +239,4 @@ LayerCreator::getConfiguration() const
   return m_cfg;
 }
 
-}  // namespace Acts
-
-#endif  // ACTS_GEOMETRYTOOLS_LAYERCREATOR_H
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Tools/PassiveLayerBuilder.hpp b/Core/include/Acts/Tools/PassiveLayerBuilder.hpp
index 011d762f2e1bd11324ee0e5d5c12e1d1cb9900fe..1ea2abae30ba7ffe4ff28ef236816db4dd887582 100644
--- a/Core/include/Acts/Tools/PassiveLayerBuilder.hpp
+++ b/Core/include/Acts/Tools/PassiveLayerBuilder.hpp
@@ -10,9 +10,7 @@
 // PassiveLayerBuilder.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_GEOMETRYTOOLS_PASSIVELAYERBUILDER_H
-#define ACTS_GEOMETRYTOOLS_PASSIVELAYERBUILDER_H 1
-
+#pragma once
 #include "Acts/Layers/Layer.hpp"
 #include "Acts/Tools/ILayerBuilder.hpp"
 #include "Acts/Utilities/Logger.hpp"
@@ -148,6 +146,4 @@ PassiveLayerBuilder::centralLayers() const
   return m_cLayers;
 }
 
-}  // end of namespace
-
-#endif  // ACTS_TOOLS_PASSIVELAYERBUILDER_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Tools/SurfaceArrayCreator.hpp b/Core/include/Acts/Tools/SurfaceArrayCreator.hpp
index 1b63ad37f20edf5e54300f0baeb32d9e2a170a90..fe1193dcf0e12517734bdd75e1e445183a10f66a 100644
--- a/Core/include/Acts/Tools/SurfaceArrayCreator.hpp
+++ b/Core/include/Acts/Tools/SurfaceArrayCreator.hpp
@@ -10,9 +10,7 @@
 // SurfaceArrayCreator.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_TOOLS_SURFACERARRAYCREATOR_H
-#define ACTS_TOOLS_SURFACERARRAYCREATOR_H 1
-
+#pragma once
 #include <boost/none.hpp>
 #include <boost/optional.hpp>
 #include "Acts/Layers/ProtoLayer.hpp"
@@ -435,6 +433,4 @@ private:
                      const std::vector<Acts::Vector2D>& locVertices) const;
 };
 
-}  // namespace Acts
-
-#endif  // ACTS_TOOLS_SURFACERARRAYCREATOR_H
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Tools/TrackingGeometryBuilder.hpp b/Core/include/Acts/Tools/TrackingGeometryBuilder.hpp
index 121899be8808626066ac4fcac6118ae6cf63f8d2..02297b8b5bbdb20659afce05eda5cacd5f8be0d6 100644
--- a/Core/include/Acts/Tools/TrackingGeometryBuilder.hpp
+++ b/Core/include/Acts/Tools/TrackingGeometryBuilder.hpp
@@ -10,9 +10,7 @@
 // TrackingGeometryBuilder.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_TOOLS_CYLINDERGEOMETRYBUILDER_H
-#define ACTS_TOOLS_CYLINDERGEOMETRYBUILDER_H 1
-
+#pragma once
 #include <list>
 #include <memory>
 #include "Acts/Tools/ITrackingGeometryBuilder.hpp"
@@ -105,6 +103,4 @@ TrackingGeometryBuilder::getConfiguration() const
   return m_cfg;
 }
 
-}  // end of namespace
-
-#endif  // ACTS_TOOLS_CYLINDERGEOMETRYBUILDER_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Tools/TrackingVolumeArrayCreator.hpp b/Core/include/Acts/Tools/TrackingVolumeArrayCreator.hpp
index 320b84bc0fe1043434a68a95f6fcb94db3bdb6fe..72516347dd76f404930130c6bb7c9066bc9dc612 100644
--- a/Core/include/Acts/Tools/TrackingVolumeArrayCreator.hpp
+++ b/Core/include/Acts/Tools/TrackingVolumeArrayCreator.hpp
@@ -10,9 +10,7 @@
 // TrackingVolumeArrayCreator.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_GEOMETRYTOOLS_TRACKINGVOLUMEARRAYCREATOR_H
-#define ACTS_GEOMETRYTOOLS_TRACKINGVOLUMEARRAYCREATOR_H
-
+#pragma once
 #include <algorithm>
 #include "Acts/Tools/ITrackingVolumeArrayCreator.hpp"
 #include "Acts/Utilities/BinnedArray.hpp"
@@ -78,6 +76,4 @@ private:
   /// logging instance
   std::unique_ptr<const Logger> m_logger;
 };
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/ApproachDescriptor.hpp b/Core/include/Acts/Utilities/ApproachDescriptor.hpp
index 34f8b2740a292c0926292687c6819b548200472f..1cf2ef404329db69f84e2fe67d7e8406b033a699 100644
--- a/Core/include/Acts/Utilities/ApproachDescriptor.hpp
+++ b/Core/include/Acts/Utilities/ApproachDescriptor.hpp
@@ -10,9 +10,7 @@
 // ApproachDescriptor.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_UTILITIES_APPROACHDESCRIPTOR_H
-#define ACTS_UTILITIES_APPROACHDESCRIPTOR_H 1
-
+#pragma once
 #include <vector>
 #include "Acts/Utilities/Definitions.hpp"
 #include "Acts/Utilities/Intersection.hpp"
@@ -75,6 +73,4 @@ public:
   containedSurfaces()
       = 0;
 };
-}
-
-#endif  // ACTS_GEOMETRYUTILS_APPROACHDESCRIPTOR_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/BFieldMapUtils.hpp b/Core/include/Acts/Utilities/BFieldMapUtils.hpp
index cf49f0bc14e3c8803dea2a27518a142e3aa7ee81..15c2746e66e6b69a98c3d192adbfa43f3822ef37 100644
--- a/Core/include/Acts/Utilities/BFieldMapUtils.hpp
+++ b/Core/include/Acts/Utilities/BFieldMapUtils.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTFW_BFIELD_BFIELDMAPUTILS_HPP
-#define ACTFW_BFIELD_BFIELDMAPUTILS_HPP
-
+#pragma once
 #include <vector>
 #include "Acts/MagneticField/InterpolatedBFieldMap.hpp"
 #include "Acts/Utilities/Units.hpp"
@@ -129,6 +127,4 @@ Acts::InterpolatedBFieldMap::FieldMapper<3, 3> fieldMapperXYZ(
     double                      BFieldUnit  = Acts::units::_T,
     bool                        firstOctant = false);
 
-}  // end of namespace Acts
-
-#endif  // ACTFW_BFIELD_BFIELDMAPUTILS_HPP
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/BinUtility.hpp b/Core/include/Acts/Utilities/BinUtility.hpp
index ba48abc34598be5976d88b2b19a290f957f121fe..e4b56f1910b742885611848da00987f7f80149dc 100644
--- a/Core/include/Acts/Utilities/BinUtility.hpp
+++ b/Core/include/Acts/Utilities/BinUtility.hpp
@@ -10,9 +10,7 @@
 // BinUtility.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_UTILITIES_BINUTILITY_H
-#define ACTS_UTILITIES_BINUTILITY_H 1
-
+#pragma once
 #include <array>
 #include <iostream>
 #include <memory>
@@ -417,6 +415,4 @@ private:
 std::ostream&
 operator<<(std::ostream& sl, const BinUtility& bgen);
 
-}  // end of namespace Acts
-
-#endif  // ACTS_UTILITIES_BINUTILITY_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/BinnedArray.hpp b/Core/include/Acts/Utilities/BinnedArray.hpp
index db3eb32f8dedc636140d5990fafef516c3a601d8..66143eeca80097961a9b1e1710558692bd767b70 100644
--- a/Core/include/Acts/Utilities/BinnedArray.hpp
+++ b/Core/include/Acts/Utilities/BinnedArray.hpp
@@ -10,9 +10,7 @@
 // BinnedArray.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_UTILITIES_BINNEDARRAY_H
-#define ACTS_UTILITIES_BINNEDARRAY_H 1
-
+#pragma once
 #include <array>
 #include <vector>
 #include "Acts/Utilities/BinUtility.hpp"
@@ -107,6 +105,4 @@ public:
   binUtility() const = 0;
 };
 
-}  // end of namespace Acts
-
-#endif  // ACTS_UTILITIES_BINNEDARRAY_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/BinnedArrayXD.hpp b/Core/include/Acts/Utilities/BinnedArrayXD.hpp
index 0f4377942e50d1f0960e24b556aaa8428c2e1f3b..f4dee908dd96d4b86566ef8b4a3ba5e3475b184c 100644
--- a/Core/include/Acts/Utilities/BinnedArrayXD.hpp
+++ b/Core/include/Acts/Utilities/BinnedArrayXD.hpp
@@ -10,9 +10,7 @@
 // BinnedArrayXD.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_UTILITIES_BINNEDARRAYXD_H
-#define ACTS_UTILITIES_BINNEDARRAYXD_H 1
-
+#pragma once
 #include <array>
 #include <iostream>
 #include <vector>
@@ -245,6 +243,4 @@ private:
   std::unique_ptr<const BinUtility> m_binUtility;
 };
 
-}  // end of namespace Acts
-
-#endif  // ACTS_UTILITIES_BINNEDARRAYXD_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/BinningData.hpp b/Core/include/Acts/Utilities/BinningData.hpp
index 75243cce5aaf821bd04c4c8517904c303f674201..ad92d9e9691547e832783dd1752e7c30fd7c7839 100644
--- a/Core/include/Acts/Utilities/BinningData.hpp
+++ b/Core/include/Acts/Utilities/BinningData.hpp
@@ -9,9 +9,7 @@
 ///////////////////////////////////////////////////////////////////
 // BinUtility.h, ACTS project
 ///////////////////////////////////////////////////////////////////
-#ifndef ACTS_UTILITIES_BINNINGDATA_H
-#define ACTS_UTILITIES_BINNINGDATA_H 1
-
+#pragma once
 #include <cmath>
 #include <iostream>
 #include <memory>
@@ -582,6 +580,4 @@ private:
     return nbelow - 1;
   }
 };
-}
-
-#endif  // ACTS_UTILITIES_BINNINGDATA_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/BinningType.hpp b/Core/include/Acts/Utilities/BinningType.hpp
index 79271dd51a9a728d557c6f3de1c063026e3c857a..1534a0491d3f3ae337890381fa7164a98cebb627 100644
--- a/Core/include/Acts/Utilities/BinningType.hpp
+++ b/Core/include/Acts/Utilities/BinningType.hpp
@@ -10,9 +10,7 @@
 // BinningType.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_UTILITIES_BINNINGTYPE_H
-#define ACTS_UTILITIES_BINNINGTYPE_H 1
-
+#pragma once
 #include <string>
 #include <vector>
 
@@ -60,5 +58,4 @@ static const std::vector<std::string> binningValueNames = {"binX",
                                                            "binH",
                                                            "binEta",
                                                            "binMag"};
-}
-#endif  // ACTS_UTILITIES_BINNINGTYPE_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/Definitions.hpp b/Core/include/Acts/Utilities/Definitions.hpp
index 69675538677b8ec4d7e12d467d944e0cbed4aa5a..61c39f9964f29ef1f08d3fcbedb32b039e5a7077 100644
--- a/Core/include/Acts/Utilities/Definitions.hpp
+++ b/Core/include/Acts/Utilities/Definitions.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_Definitions_H
-#define ACTS_Definitions_H
-
+#pragma once
 // API addons
 #define EIGEN_MATRIXBASE_PLUGIN "Acts/Utilities/detail/MatrixBasePlugin.hpp"
 #define EIGEN_MATRIX_PLUGIN "Acts/Utilities/detail/MatrixPlugin.hpp"
@@ -145,6 +143,4 @@ typedef Eigen::Matrix<double, 3, 1> Vector3D;
 typedef Eigen::Matrix<double, 2, 1> Vector2D;
 typedef Eigen::Matrix<double, 3, 3> RotationMatrix3D;
 
-}  // end of namespace Acts
-
-#endif
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/GeometryID.hpp b/Core/include/Acts/Utilities/GeometryID.hpp
index c9e1c2abbbd9db5cfcfd2d5b7dae82c60c3b2f33..3d9739152e26ac8213bcddd3babdd8db1deb3f84 100644
--- a/Core/include/Acts/Utilities/GeometryID.hpp
+++ b/Core/include/Acts/Utilities/GeometryID.hpp
@@ -10,9 +10,7 @@
 // GeometryID.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_GEOMETRYUTILS_GEOMETRYID_H
-#define ACTS_GEOMETRYUTILS_GEOMETRYID_H 1
-
+#pragma once
 #include <iostream>
 #include "Acts/Utilities/Helpers.hpp"
 
@@ -139,6 +137,4 @@ operator>=(const GeometryID& one, const GeometryID& two);
 /// Overload of << operator for std::ostream for debug output
 std::ostream&
 operator<<(std::ostream& sl, const GeometryID& tddID);
-}
-
-#endif  // ACTS_GEOMETRYUTILS_GEOMETRYID_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/GeometryObject.hpp b/Core/include/Acts/Utilities/GeometryObject.hpp
index 39b1bcd60d9e714501a5d17f6fc8d0bd267cebe5..cb4596f0bcf4dab1e70863a8c8d752877388fdb4 100644
--- a/Core/include/Acts/Utilities/GeometryObject.hpp
+++ b/Core/include/Acts/Utilities/GeometryObject.hpp
@@ -10,9 +10,7 @@
 // GeometryObject.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_GEOMETRYUTILS_GEOMETRYOBJECT_H
-#define ACTS_GEOMETRYUTILS_GEOMETRYOBJECT_H
-
+#pragma once
 #include "Acts/Utilities/BinningType.hpp"
 #include "Acts/Utilities/Definitions.hpp"
 #include "Acts/Utilities/GeometryID.hpp"
@@ -117,6 +115,4 @@ GeometryObject::binningPositionValue(BinningValue bValue) const
     return 0.;
   }
 }
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/GeometryObjectSorter.hpp b/Core/include/Acts/Utilities/GeometryObjectSorter.hpp
index 463d4311c88491decde33d9985a6db7221e074c9..7b0de6a22518ddd3eba9c9e1489683919438fb8b 100644
--- a/Core/include/Acts/Utilities/GeometryObjectSorter.hpp
+++ b/Core/include/Acts/Utilities/GeometryObjectSorter.hpp
@@ -10,9 +10,7 @@
 // GeometryObjectSorter.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_GEOMETRYUTILS_GEOMETRYOBJECTSORTER_H
-#define ACTS_GEOMETRYUTILS_GEOMETRYOBJECTSORTER_H 1
-
+#pragma once
 #include "Definitions.hpp"
 
 namespace Acts {
@@ -209,6 +207,4 @@ protected:
   ObjectSorterT<Vector3D>            m_objectSorter;
   std::shared_ptr<const Transform3D> m_transform;
 };
-}
-
-#endif  // ACTS_GEOMETRYUTILS_GEOMETRYOBJECTSORTER_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/GeometrySignature.hpp b/Core/include/Acts/Utilities/GeometrySignature.hpp
index 2eeb973e157f8d3e0626b2595377edc42872cf64..5c05297c8bb7af9d6689603398144e15d835af46 100644
--- a/Core/include/Acts/Utilities/GeometrySignature.hpp
+++ b/Core/include/Acts/Utilities/GeometrySignature.hpp
@@ -10,9 +10,7 @@
 // GeometrySignature.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_GEOMETRYUTILS_GEOMETRYSIGNATURE_H
-#define ACTS_GEOMETRYUTILS_GEOMETRYSIGNATURE_H 1
-
+#pragma once
 namespace Acts {
 
 ///@class GeometrySignature
@@ -42,6 +40,4 @@ enum GeometryType {
   NumberOfGeometryTypes = 3
 };
 
-}  // end of namespace
-
-#endif  // ACTS_GEOMETRYUTILS_GEOMETRYSIGNATURE_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/GeometryStatics.hpp b/Core/include/Acts/Utilities/GeometryStatics.hpp
index 19c54de2caf5007e9325164503f9e641f0f9d6a2..16ac66440edcccaa4ac16f245413ded3c6e23c9b 100644
--- a/Core/include/Acts/Utilities/GeometryStatics.hpp
+++ b/Core/include/Acts/Utilities/GeometryStatics.hpp
@@ -10,9 +10,7 @@
 // GeometryStatics.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_GEOMETYRUTILS_GEOMETRYSTATICS_H
-#define ACTS_GEOMETYRUTILS_GEOMETRYSTATICS_H 1
-
+#pragma once
 #include "Acts/Utilities/Definitions.hpp"
 
 /// Define statics for Geometry in Tracking
@@ -41,6 +39,4 @@ static const Vector3D s_origin(0, 0, 0);  //!< origin position
 static const double helper[9] = {0., 1., 0., 1., 0., 0., 0., 0., -1.};
 
 static const Acts::RotationMatrix3D s_idRotationZinverse(helper);
-}
-
-#endif  // ACTS_GEOMETYRUTILS_GEOMETRYSTATICS_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/Helpers.hpp b/Core/include/Acts/Utilities/Helpers.hpp
index 51dda834ac9082a9af62397cd12aec68b5e4955d..2028857044467623da138d34fae68028970f80ad 100644
--- a/Core/include/Acts/Utilities/Helpers.hpp
+++ b/Core/include/Acts/Utilities/Helpers.hpp
@@ -10,9 +10,7 @@
 // AlgebraHelper.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_HELPERS_H
-#define ACTS_HELPERS_H 1
-
+#pragma once
 // STL include(s)
 #include <cmath>
 #include <iomanip>
@@ -341,6 +339,4 @@ getRotateZ3D(double angle)
   return transf;
 }
 
-}  // end of Acts namespace
-
-#endif
+}  // end of Acts namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/IAxis.hpp b/Core/include/Acts/Utilities/IAxis.hpp
index 30112f381ea0f7f64dd10d1f95b16b8104fd6031..edf895977534b75297c5ec03f8d6ab535899e1c4 100644
--- a/Core/include/Acts/Utilities/IAxis.hpp
+++ b/Core/include/Acts/Utilities/IAxis.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_UTILITIES_IAXIS_H
-#define ACTS_UTILITIES_IAXIS_H
-
+#pragma once
 #include <vector>
 
 namespace Acts {
@@ -64,6 +62,4 @@ public:
   virtual size_t
   getNBins() const = 0;
 };
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/Identifier.hpp b/Core/include/Acts/Utilities/Identifier.hpp
index dd66d975faf205ec8c895d9febaca4552ef9cea7..18e3029a5db84ca973e5fcd128ae2845d8402c79 100644
--- a/Core/include/Acts/Utilities/Identifier.hpp
+++ b/Core/include/Acts/Utilities/Identifier.hpp
@@ -10,9 +10,7 @@
 // Identifier.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_CORE_IDENTIFIER_H
-#define ACTS_CORE_IDENTIFIER_H 1
-
+#pragma once
 #ifdef ACTS_CORE_IDENTIFIER_PLUGIN
 #include ACTS_CORE_IDENTIFIER_PLUGIN
 #else
@@ -240,6 +238,4 @@ Identifier::is_valid() const
   return (!(max_value == m_id));
 }
 
-#endif  // ACTS_CORE_IDENTIFIER_PLUGIN
-
-#endif  // ACTS_CORE_IDENTIFIER_H
+#endif  // ACTS_CORE_IDENTIFIER_PLUGIN
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/InstanceFactory.hpp b/Core/include/Acts/Utilities/InstanceFactory.hpp
index 14d49ed8e87c052c41c83e7f5b79ec695a7b42ef..7c9fcc6ecf207779cf8876eb50680ad08513d489 100644
--- a/Core/include/Acts/Utilities/InstanceFactory.hpp
+++ b/Core/include/Acts/Utilities/InstanceFactory.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_PLUGINS_JSONPLUGIN_INSTANCEFACTORY_H
-#define ACTS_PLUGINS_JSONPLUGIN_INSTANCEFACTORY_H 1
-
+#pragma once
 #include <boost/functional/value_factory.hpp>
 #include <map>
 #include "Acts/Utilities/ThrowAssert.hpp"
@@ -133,6 +131,4 @@ private:
   std::map<std::string, SurfaceFactory>       m_surfaces;
 };
 
-}  // namespace Acts
-
-#endif
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/Intersection.hpp b/Core/include/Acts/Utilities/Intersection.hpp
index 49a48385ec7e3ac2f0bbf43718c67bd288cd7567..7a0ca9615d307a2998596020fabf0c4ea4b35f75 100644
--- a/Core/include/Acts/Utilities/Intersection.hpp
+++ b/Core/include/Acts/Utilities/Intersection.hpp
@@ -10,9 +10,7 @@
 // Intersection.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_GEOMETRYUTILS_INTERSECTION_H
-#define ACTS_GEOMETRYUTILS_INTERSECTION_H
-
+#pragma once
 #include <limits>
 #include "Definitions.hpp"
 
@@ -133,6 +131,4 @@ public:
     return (intersection < fi.intersection);
   }
 };
-}
-
-#endif  // ACTS_GEOMETRYUTILS_INTERSECTION_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/Logger.hpp b/Core/include/Acts/Utilities/Logger.hpp
index ab75d1aef84bd4fe2907c066a81732752d24847a..823115722586ec455eb7438d4fa9e7417b7ea372 100644
--- a/Core/include/Acts/Utilities/Logger.hpp
+++ b/Core/include/Acts/Utilities/Logger.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_LOGGER_H
-#define ACTS_LOGGER_H 1
-
+#pragma once
 // STL include(s)
 #include <ctime>
 #include <functional>
@@ -605,6 +603,4 @@ getDefaultLogger(const std::string&    name,
                  const Logging::Level& lvl,
                  std::ostream*         log_stream = &std::cout);
 
-}  // end of namespace Acts
-
-#endif  // ACTS_LOGGER_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/MaterialInteraction.hpp b/Core/include/Acts/Utilities/MaterialInteraction.hpp
index caaf3b8b3b50d9ad939a0d2e6f6fbdcfc969ec75..33850beb01ce32deff9f14a3fc29afeed14d9565 100644
--- a/Core/include/Acts/Utilities/MaterialInteraction.hpp
+++ b/Core/include/Acts/Utilities/MaterialInteraction.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_EXTRAPOLATIONUTILS_MATERIALINTERACTION_H
-#define ACTS_EXTRAPOLATIONUTILS_MATERIALINTERACTION_H 1
-
+#pragma once
 #include "Acts/EventData/ParticleDefinitions.hpp"
 #include "Acts/Material/Material.hpp"
 #include "Acts/Utilities/Definitions.hpp"
@@ -86,6 +84,4 @@ radiationEnergyLoss(double                p,
 double
 sigmaMS(double dInX0, double p, double beta);
 
-}  // end of namespace
-
-#endif
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/ParameterDefinitions.hpp b/Core/include/Acts/Utilities/ParameterDefinitions.hpp
index 73ff9340818e6e744f947919144b2153a1ab75d4..e5318d9ba64279ba0dbab5339cc30b0ac68e72e5 100644
--- a/Core/include/Acts/Utilities/ParameterDefinitions.hpp
+++ b/Core/include/Acts/Utilities/ParameterDefinitions.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_PARAMETERDEFINITIONS_H
-#define ACTS_PARAMETERDEFINITIONS_H 1
-
+#pragma once
 #ifdef ACTS_PARAMETER_DEFINITIONS_PLUGIN
 #include ACTS_PARAMETER_DEFINITIONS_PLUGIN
 #endif
@@ -53,6 +51,4 @@ static_assert(Acts::eLOC_Z0 == Acts::eLOC_0 or Acts::eLOC_Z0 == Acts::eLOC_1,
 
 /// check for par_type_t definition
 static_assert(sizeof(Acts::par_type_t<Acts::eLOC_0>) > 0,
-              "'par_type_t' is not defined");
-
-#endif  //  ACTS_PARAMETERDEFINITIONS_H
+              "'par_type_t' is not defined");
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/ParameterTypes.hpp b/Core/include/Acts/Utilities/ParameterTypes.hpp
index c4b6ae335b20bcfb8ccd4b53ac615c9f247f0ff6..310c761b0691f5f819c1f9308661cd6626dc2ae3 100644
--- a/Core/include/Acts/Utilities/ParameterTypes.hpp
+++ b/Core/include/Acts/Utilities/ParameterTypes.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_PARAMETERTYPES_H
-#define ACTS_PARAMETERTYPES_H 1
-
+#pragma once
 #include <algorithm>
 #include <cmath>
 
@@ -174,6 +172,4 @@ struct cyclic_parameter
 //  template<typename ParameterPolicy,typename ParameterPolicy::par_id_type
 //  parID>
 //  struct parameter_traits;
-}  // end of namespace Acts
-
-#endif  // ACTS_PARAMETERTYPES
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/ThrowAssert.hpp b/Core/include/Acts/Utilities/ThrowAssert.hpp
index c52e814fafa8bcee6514bf54162b66a92d461a50..f0e17a4157a997e5adb342b57fe3c0dd12b289e3 100644
--- a/Core/include/Acts/Utilities/ThrowAssert.hpp
+++ b/Core/include/Acts/Utilities/ThrowAssert.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_UTILITIES_THROWASSERT_H
-#define ACTS_UTILITIES_THROWASSERT_H 1
-
+#pragma once
 #include <exception>
 #include <iostream>
 #include <sstream>
@@ -85,6 +83,4 @@ private:
         __FILE__,                                                              \
         __LINE__,                                                              \
         (Acts::AssertionFailureException::StreamFormatter() << MESSAGE));      \
-  }
-
-#endif
+  }
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/Units.hpp b/Core/include/Acts/Utilities/Units.hpp
index 9dfd5c4d67bc583e0ae0df127acac0814fa1e17a..d660db767be9cf9ccc6bacb6a3fdbc20619975a5 100644
--- a/Core/include/Acts/Utilities/Units.hpp
+++ b/Core/include/Acts/Utilities/Units.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_UNITS_HPP
-#define ACTS_UNITS_HPP 1
-
+#pragma once
 namespace Acts {
 
 /// @brief Unit and conversion constants
@@ -45,7 +43,7 @@ namespace units {
 #ifdef DOXYGEN
   const double _m = unspecified;
 #else
-  const double _m   = 1e3;
+  const double _m = 1e3;
 #endif  // DOXYGEN
   const double _km = 1e3 * _m;
   const double _cm = 1e-2 * _m;
@@ -285,5 +283,4 @@ namespace units {
   Nat2SI<MASS>(const double m);
 }  // namespace units
 
-}  // namespace Acts
-#endif  // ACTS_UNITS_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/VariantData.hpp b/Core/include/Acts/Utilities/VariantData.hpp
index b9de57277c2d7dfec387c43ae9d199a4de054e74..f8f373673941f3de59bff1f96903059566c1cbb7 100644
--- a/Core/include/Acts/Utilities/VariantData.hpp
+++ b/Core/include/Acts/Utilities/VariantData.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_UTILITIES_VARIANTDATA_H
-#define ACTS_UTILITIES_VARIANTDATA_H 1
-
+#pragma once
 // This file is a "Hello, world!" in C++ language by GCC for wandbox.
 #include <boost/variant.hpp>
 #include <iomanip>
@@ -607,6 +605,4 @@ from_variant<Vector2D>(const variant_data& data_)
   return vec;
 }
 
-}  // namespace Acts
-
-#endif
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/VariantDataFwd.hpp b/Core/include/Acts/Utilities/VariantDataFwd.hpp
index 9000720c7e67a67fc9f35a82dc8412d81cff05b0..c98dd471b2b904877fb62fd65774ee051e577829 100644
--- a/Core/include/Acts/Utilities/VariantDataFwd.hpp
+++ b/Core/include/Acts/Utilities/VariantDataFwd.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_UTILITIES_VARIANTDATA_FWD_H
-#define ACTS_UTILITIES_VARIANTDATA_FWD_H 1
-
+#pragma once
 #include <boost/variant/recursive_wrapper.hpp>
 #include <boost/variant/variant_fwd.hpp>
 #include <iostream>
@@ -30,5 +28,4 @@ using variant_data = boost::variant<int,
                                     bool,
                                     boost::recursive_wrapper<variant_map>,
                                     boost::recursive_wrapper<variant_vector>>;
-}
-#endif
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/detail/DefaultParameterDefinitions.hpp b/Core/include/Acts/Utilities/detail/DefaultParameterDefinitions.hpp
index 46e79949834fdf9b4553decbcb027789ea045ff2..cc7af3f620d81894f0df57d0bc21b80a657c5214 100644
--- a/Core/include/Acts/Utilities/detail/DefaultParameterDefinitions.hpp
+++ b/Core/include/Acts/Utilities/detail/DefaultParameterDefinitions.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_DEFAULTPARAMETERDEFINITIONS_H
-#define ACTS_DEFAULTPARAMETERDEFINITIONS_H 1
-
+#pragma once
 // STL include(s)
 #include <cmath>
 
@@ -92,6 +90,4 @@ struct par_type<ParDef::eQOP>
 {
   typedef unbound_parameter type;
 };
-}  // end of namespace Acts
-
-#endif  // ACTS_DEFAULTPARAMETERDEFINITIONS_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/detail/MPL/all_of.hpp b/Core/include/Acts/Utilities/detail/MPL/all_of.hpp
index 7984e29f6b737ed6f98e2a5e4de0f34a8705961e..1da5a9413c8e87ee91810cc5f73c79adee475eda 100644
--- a/Core/include/Acts/Utilities/detail/MPL/all_of.hpp
+++ b/Core/include/Acts/Utilities/detail/MPL/all_of.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_ALL_OF_HPP
-#define ACTS_ALL_OF_HPP 1
-
+#pragma once
 #include <type_traits>
 
 namespace Acts {
@@ -32,5 +30,4 @@ namespace detail {
   constexpr bool all_of_v = all_of<values...>::value;
 }  // namespace detail
 
-}  // namespace Acts
-#endif  // ACTS_ALL_OF_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/detail/MPL/any_of.hpp b/Core/include/Acts/Utilities/detail/MPL/any_of.hpp
index 6aa1dd414418a3cc565b285fbc9f436480d271c0..6eee966f0b1cfcf2561fd56330fd2806da4e3b17 100644
--- a/Core/include/Acts/Utilities/detail/MPL/any_of.hpp
+++ b/Core/include/Acts/Utilities/detail/MPL/any_of.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_ANY_OF_HPP
-#define ACTS_ANY_OF_HPP 1
-
+#pragma once
 #include <type_traits>
 
 namespace Acts {
@@ -32,5 +30,4 @@ namespace detail {
   constexpr bool any_of_v = any_of<values...>::value;
 }  // namespace detail
 
-}  // namespace Acts
-#endif  // ACTS_ANY_OF_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/detail/MPL/are_sorted.hpp b/Core/include/Acts/Utilities/detail/MPL/are_sorted.hpp
index b3b720faf80069ad086cce2bad08056c3671473e..5e37eeafb02f40657561b0d8932fe10195d500ae 100644
--- a/Core/include/Acts/Utilities/detail/MPL/are_sorted.hpp
+++ b/Core/include/Acts/Utilities/detail/MPL/are_sorted.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_ARE_SORTED_H
-#define ACTS_ARE_SORTED_H 1
-
+#pragma once
 namespace Acts {
 /// @cond detail
 namespace detail {
@@ -69,6 +67,4 @@ namespace detail {
   /// @endcond
 }  // end of namespace detail
 /// @endcond
-}  // end of namespace Acts
-
-#endif  // ACTS_ARE_SORTED_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/detail/MPL/are_within.hpp b/Core/include/Acts/Utilities/detail/MPL/are_within.hpp
index f249e341e819bcdaeb764a2cc8eb65d79878c0f7..9b77e549880bed7a141077cbe3d1afe7222fe6bc 100644
--- a/Core/include/Acts/Utilities/detail/MPL/are_within.hpp
+++ b/Core/include/Acts/Utilities/detail/MPL/are_within.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_ARE_WITHIN_H
-#define ACTS_ARE_WITHIN_H 1
-
+#pragma once
 namespace Acts {
 /// @cond detail
 namespace detail {
@@ -50,6 +48,4 @@ namespace detail {
   /// @endcond
 }  // end of namespace detail
 /// @endcond
-}  // end of namespace Acts
-
-#endif  // ACTS_ARE_WITHIN_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/detail/MPL/at_index.hpp b/Core/include/Acts/Utilities/detail/MPL/at_index.hpp
index bbb76da3b60979422f104d8d890193b0d25ded47..e4ddd3c98084cbe2c11bddf7815850e1e104e84c 100644
--- a/Core/include/Acts/Utilities/detail/MPL/at_index.hpp
+++ b/Core/include/Acts/Utilities/detail/MPL/at_index.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_AT_INDEX_H
-#define ACTS_AT_INDEX_H 1
-
+#pragma once
 namespace Acts {
 /// @cond detail
 namespace detail {
@@ -41,6 +39,4 @@ namespace detail {
   /// @endcond
 }  // end of namespace detail
 /// @endcond
-}  // end of namespace Acts
-
-#endif  // ACTS_GET_POSITION_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/detail/MPL/boost_mpl_helper.hpp b/Core/include/Acts/Utilities/detail/MPL/boost_mpl_helper.hpp
index c01dd6e486d7153b699bddd6dde9571a673616dc..29824a420dbbf6e5010afa81c9d9eef316f0191a 100644
--- a/Core/include/Acts/Utilities/detail/MPL/boost_mpl_helper.hpp
+++ b/Core/include/Acts/Utilities/detail/MPL/boost_mpl_helper.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_BOOST_MPL_HELPER_HPP
-#define ACTS_BOOST_MPL_HELPER_HPP 1
-
+#pragma once
 #include <boost/mpl/fold.hpp>
 #include <boost/mpl/inserter.hpp>
 #include <boost/mpl/set.hpp>
@@ -78,6 +76,4 @@ namespace detail {
 
 }  // namespace detail
 
-}  // namespace Acts
-
-#endif  // ACTS_BOOST_MPL_HELPER_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/detail/MPL/get_position.hpp b/Core/include/Acts/Utilities/detail/MPL/get_position.hpp
index a8f8c1e493642fe0ca10a5d6ebbd57d405a568b2..d654aac106858fb9b4bd4cac8f62a515c7d1343f 100644
--- a/Core/include/Acts/Utilities/detail/MPL/get_position.hpp
+++ b/Core/include/Acts/Utilities/detail/MPL/get_position.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_GET_POSITION_H
-#define ACTS_GET_POSITION_H 1
-
+#pragma once
 namespace Acts {
 /// @cond detail
 namespace detail {
@@ -43,6 +41,4 @@ namespace detail {
   /// @endcond
 }  // end of namespace detail
 /// @endcond
-}  // end of namespace Acts
-
-#endif  // ACTS_GET_POSITION_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/detail/MPL/has_duplicates.hpp b/Core/include/Acts/Utilities/detail/MPL/has_duplicates.hpp
index a3e20d4ab32c045fe902d30200e535adac0e47a9..35bd8493a96a8aeb534bbef3beccb849f0f577b2 100644
--- a/Core/include/Acts/Utilities/detail/MPL/has_duplicates.hpp
+++ b/Core/include/Acts/Utilities/detail/MPL/has_duplicates.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_HAS_DUPLICATES_HPP
-#define ACTS_HAS_DUPLICATES_HPP 1
-
+#pragma once
 namespace Acts {
 
 namespace detail {
@@ -51,5 +49,4 @@ namespace detail {
   constexpr bool has_duplicates_v = has_duplicates<Args...>::value;
 }  // namespace detail
 
-}  // namespace Acts
-#endif  // ACTS_HAS_DUPLICATES_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/detail/MPL/is_contained.hpp b/Core/include/Acts/Utilities/detail/MPL/is_contained.hpp
index 087109bc2fa26a02a3305a16d03d808010731097..7d6d9683ce09910532003a004efd120812bbd06c 100644
--- a/Core/include/Acts/Utilities/detail/MPL/is_contained.hpp
+++ b/Core/include/Acts/Utilities/detail/MPL/is_contained.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_IS_CONTAINED_H
-#define ACTS_IS_CONTAINED_H 1
-
+#pragma once
 namespace Acts {
 /// @cond detail
 namespace detail {
@@ -53,6 +51,4 @@ namespace detail {
   /// @endcond
 }  // end of namespace detail
 /// @endcond
-}  // end of namespace Acts
-
-#endif  // ACTS_IS_CONTAINED_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/detail/MPL/type_collector.hpp b/Core/include/Acts/Utilities/detail/MPL/type_collector.hpp
index a81396cf048d708e5172690bd1683714b0a5e28e..8b84252d75167e622298a8ad55a34de9f2f41772 100644
--- a/Core/include/Acts/Utilities/detail/MPL/type_collector.hpp
+++ b/Core/include/Acts/Utilities/detail/MPL/type_collector.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_TYPE_COLLECTOR_HPP
-#define ACTS_TYPE_COLLECTOR_HPP 1
-
+#pragma once
 #include <boost/mpl/set.hpp>
 #include <type_traits>
 #include "Acts/Utilities/detail/MPL/boost_mpl_helper.hpp"
@@ -137,6 +135,4 @@ namespace detail {
   using type_collector_t = typename type_collector<extractor, traits...>::type;
 }  // namespace detail
 
-}  // namespace Acts
-
-#endif  // ACTS_TYPE_COLLECTOR_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/detail/MatrixBasePlugin.hpp b/Core/include/Acts/Utilities/detail/MatrixBasePlugin.hpp
index 0a77e232e26c7967d9a0dcb0b9db9819f1650545..30b341e31c3ab9d2b37c9f3149fca544acc65023 100644
--- a/Core/include/Acts/Utilities/detail/MatrixBasePlugin.hpp
+++ b/Core/include/Acts/Utilities/detail/MatrixBasePlugin.hpp
@@ -10,9 +10,7 @@
 // AmgMatrixPlugin.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef EVENTPRIMITIVES_AMGMATRIXPLUGIN_H
-#define EVENTPRIMITIVES_AMGMATRIXPLUGIN_H
-
+#pragma once
 //#include <cmath>
 
 /** This is a plugin that makes Eigen look like CLHEP
@@ -148,6 +146,4 @@ inline Matrix<Scalar,
 similarityT(const MatrixBase<OtherDerived>& m) const
 {
   return m.transpose() * (this->derived() * m);
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/detail/MatrixPlugin.hpp b/Core/include/Acts/Utilities/detail/MatrixPlugin.hpp
index 0de7ebeda28841a292b3e1b53a02fad4921e22f0..ad875f1ebda9bdf5dea4d313f3f0076b0febd3a9 100644
--- a/Core/include/Acts/Utilities/detail/MatrixPlugin.hpp
+++ b/Core/include/Acts/Utilities/detail/MatrixPlugin.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef EVENTPRIMITIVES_SYMMETRICMATRIXHELPERS_H
-#define EVENTPRIMITIVES_SYMMETRICMATRIXHELPERS_H
-
+#pragma once
 #include <cmath>
 
 //////////////////////////////////////////////////////////////////////
@@ -266,6 +264,4 @@ similaritySym5(
   Vn[23] = Vn[19];
 
   return out;
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/detail/RealQuadraticEquation.hpp b/Core/include/Acts/Utilities/detail/RealQuadraticEquation.hpp
index 08fe0480ab90634133acfb1e942aedccc64920b3..26c2f0b31a410fbb8e7de6b3592a0d8d4206b9cf 100644
--- a/Core/include/Acts/Utilities/detail/RealQuadraticEquation.hpp
+++ b/Core/include/Acts/Utilities/detail/RealQuadraticEquation.hpp
@@ -10,9 +10,7 @@
 // RealQuadraticEquation.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_SURFACES_REALQUADRATICEQUATION_H
-#define ACTS_SURFACES_REALQUADRATICEQUATION_H
-
+#pragma once
 #include <cmath>
 #include <utility>
 
@@ -74,6 +72,4 @@ namespace detail {
   };
 
 }  // namespace detail
-}  // namespace Acts
-
-#endif  //  ACTS_SURFACES_REALQUADRATICEQUATION_H
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/detail/TransformPlugin.hpp b/Core/include/Acts/Utilities/detail/TransformPlugin.hpp
index d46bcadc1da38dcfe1a8d4f60bd1b587be371db9..ffc64c7b83437f4bc60ba9faa4a171e917dfc917 100644
--- a/Core/include/Acts/Utilities/detail/TransformPlugin.hpp
+++ b/Core/include/Acts/Utilities/detail/TransformPlugin.hpp
@@ -10,9 +10,7 @@
 // GeoPrimitivesHelpers.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef EVENTPRIMITIVES_AMGTRANSFORMPLUGIN_H
-#define EVENTPRIMITIVES_AMGTRANSFORMPLUGIN_H
-
+#pragma once
 inline explicit Transform(const Vector3d& rotationMatrixCol0,
                           const Vector3d& rotationMatrixCol1,
                           const Vector3d& rotationMatrixCol2)
@@ -60,6 +58,4 @@ inline explicit Transform(const Vector3d& rotationMatrixCol0,
   m_matrix.block(0, 2, 3, 1) = rotationMatrixCol2;
   m_matrix.block(0, 3, 3, 1) = translation;
   if (int(Mode) == Affine) makeAffine();
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Utilities/detail/periodic.hpp b/Core/include/Acts/Utilities/detail/periodic.hpp
index d26d9eac6990bb24e49337bba2c0173ba52aaba4..f252b2cc80b21fa14244064d6e46b70631837b34 100644
--- a/Core/include/Acts/Utilities/detail/periodic.hpp
+++ b/Core/include/Acts/Utilities/detail/periodic.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_SEEDING_PERIODIC_HPP
-#define ACTS_SEEDING_PERIODIC_HPP
-
+#pragma once
 #include <cmath>
 
 namespace Acts {
@@ -44,6 +42,4 @@ namespace detail {
   }
 
 }  // namespace detail
-}  // namespace Acts
-
-#endif  // ACTS_SEEDING_PERIODIC_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Volumes/AbstractVolume.hpp b/Core/include/Acts/Volumes/AbstractVolume.hpp
index 586bf3cd93cda448353e313a489f3609fd031d45..9a39a15ffd6a7dfa199378718fb7c3742cf472ea 100644
--- a/Core/include/Acts/Volumes/AbstractVolume.hpp
+++ b/Core/include/Acts/Volumes/AbstractVolume.hpp
@@ -10,9 +10,7 @@
 // AbstractVolume.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_VOLUMES_ABSTRACTVOLUME_H
-#define ACTS_VOLUMES_ABSTRACTVOLUME_H
-
+#pragma once
 #include <vector>
 #include "Acts/Utilities/Definitions.hpp"
 #include "Acts/Volumes/BoundarySurfaceT.hpp"
@@ -90,6 +88,4 @@ private:
   std::vector<BoundarySurfacePtr> m_boundarySurfaces;
 };
 
-}  // end of namespace
-
-#endif  // ACTS_VOLUMES_ABSTRACTVOLUME_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Core/include/Acts/Volumes/BoundarySurfaceFace.hpp b/Core/include/Acts/Volumes/BoundarySurfaceFace.hpp
index 051752a5f0c33a770de74f01394f21086a4cf313..260fa111881ec27170f302e9c920b22d677c64dc 100644
--- a/Core/include/Acts/Volumes/BoundarySurfaceFace.hpp
+++ b/Core/include/Acts/Volumes/BoundarySurfaceFace.hpp
@@ -10,9 +10,7 @@
 // BoundarySurfaceFace.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_VOLUMES_BOUNDARYSURFACEFACE_H
-#define ACTS_VOLUMES_BOUNDARYSURFACEFACE_H 1
-
+#pragma once
 namespace Acts {
 
 ///  @enum BoundarySurfaceFace
@@ -61,6 +59,4 @@ enum BoundarySurfaceFace {
 
 /// @brief specify the inside/outside with respect to the normal vector
 enum BoundaryOrientation { insideVolume = -1, outsideVolume = 1 };
-}
-
-#endif  // ACTS_VOLUMES_BOUNDARYSURFACEFACE_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Volumes/BoundarySurfaceT.hpp b/Core/include/Acts/Volumes/BoundarySurfaceT.hpp
index 922de6dc7641e52a05dcf658403e3c3b6d1a5f5c..31a8e45a4ecaea0e5f427294965cb65d00b01fb9 100644
--- a/Core/include/Acts/Volumes/BoundarySurfaceT.hpp
+++ b/Core/include/Acts/Volumes/BoundarySurfaceT.hpp
@@ -10,9 +10,7 @@
 // BoundarySurfaceT.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_VOLUMES_BOUNDARYSURFACET_H
-#define ACTS_VOLUMES_BOUNDARYSURFACET_H
-
+#pragma once
 #include <memory>
 #include "Acts/Utilities/BinnedArray.hpp"
 #include "Acts/Utilities/Definitions.hpp"
@@ -217,6 +215,4 @@ BoundarySurfaceT<T>::attachedVolume(const Vector3D& pos,
                                     : m_insideVolume;
   return attVolume;
 }
-}  // end of namespace Acts
-
-#endif  // ACTS_VOLUMES_BOUNDARYSURFACET_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Volumes/CuboidVolumeBounds.hpp b/Core/include/Acts/Volumes/CuboidVolumeBounds.hpp
index 46a9fe27029c306956da3150f53a4ee729281f86..35d0994920d2faff97e7d957c4b65f211bf10496 100644
--- a/Core/include/Acts/Volumes/CuboidVolumeBounds.hpp
+++ b/Core/include/Acts/Volumes/CuboidVolumeBounds.hpp
@@ -10,9 +10,7 @@
 // CuboidVolumeBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_VOLUMES_CUBOIDVOLUMESBOUNDS_H
-#define ACTS_VOLUMES_CUBOIDVOLUMESBOUNDS_H 1
-
+#pragma once
 #include <cmath>
 #include "Acts/Utilities/Definitions.hpp"
 #include "Acts/Volumes/VolumeBounds.hpp"
@@ -185,6 +183,4 @@ CuboidVolumeBounds::dumpT(T& dt) const
      << ", " << m_valueStore.at(bv_halfZ) << ")";
   return dt;
 }
-}
-
-#endif  // ACTS_VOLUMES_CUBOIDVOLUMESBOUNDS_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Volumes/CylinderVolumeBounds.hpp b/Core/include/Acts/Volumes/CylinderVolumeBounds.hpp
index 0442ae6459b01f6e513d9b748c2bda36d0c5252a..2892e7842710788b130e44c8de0f66e9028d27b9 100644
--- a/Core/include/Acts/Volumes/CylinderVolumeBounds.hpp
+++ b/Core/include/Acts/Volumes/CylinderVolumeBounds.hpp
@@ -10,9 +10,7 @@
 // CylinderVolumeBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_VOLUMES_CYLINDERVOLUMESBOUNDS_H
-#define ACTS_VOLUMES_CYLINDERVOLUMESBOUNDS_H 1
-
+#pragma once
 #include <cmath>
 #include "Acts/Utilities/Definitions.hpp"
 #include "Acts/Volumes/VolumeBounds.hpp"
@@ -296,6 +294,4 @@ CylinderVolumeBounds::dumpT(T& tstream) const
           << m_valueStore.at(bv_halfZ);
   return tstream;
 }
-}
-
-#endif  // ACTS_VOLUMES_CYLINDERVOLUMESBOUNDS_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Volumes/DoubleTrapezoidVolumeBounds.hpp b/Core/include/Acts/Volumes/DoubleTrapezoidVolumeBounds.hpp
index 9abe816e8af267bf99642e9fa758e60a0f989f94..54b639f708077f303e08b263bc1bc862227865d8 100644
--- a/Core/include/Acts/Volumes/DoubleTrapezoidVolumeBounds.hpp
+++ b/Core/include/Acts/Volumes/DoubleTrapezoidVolumeBounds.hpp
@@ -10,9 +10,7 @@
 // DoubleTrapezoidVolumeBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_VOLUMES_DOUBLETRAPEZOIDVOLUMESBOUNDS_H
-#define ACTS_VOLUMES_DOUBLETRAPEZOIDVOLUMESBOUNDS_H 1
-
+#pragma once
 #include "Acts/Utilities/Definitions.hpp"
 #include "Acts/Volumes/VolumeBounds.hpp"
 
@@ -275,6 +273,4 @@ DoubleTrapezoidVolumeBounds::dumpT(T& dT) const
      << ", " << m_valueStore.at(bv_halfZ) << ")";
   return dT;
 }
-}
-
-#endif  // ACTS_VOLUMES_DOUBLETRAPEZOIDVOLUMESBOUNDS_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Volumes/TrapezoidVolumeBounds.hpp b/Core/include/Acts/Volumes/TrapezoidVolumeBounds.hpp
index c4552fc41dbb11f5c13da27e573983f1a60175a2..aa8b642c0d1226feeb23cb079e908c55408b22eb 100644
--- a/Core/include/Acts/Volumes/TrapezoidVolumeBounds.hpp
+++ b/Core/include/Acts/Volumes/TrapezoidVolumeBounds.hpp
@@ -10,9 +10,7 @@
 // TrapezoidVolumeBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_VOLUMES_TRAPEZOIDVOLUMESBOUNDS_H
-#define ACTS_VOLUMES_TRAPEZOIDVOLUMESBOUNDS_H 1
-
+#pragma once
 #include "Acts/Utilities/Definitions.hpp"
 #include "Acts/Volumes/VolumeBounds.hpp"
 
@@ -235,6 +233,4 @@ TrapezoidVolumeBounds::dumpT(T& dt) const
      << ")";
   return dt;
 }
-}
-
-#endif  // ACTS_VOLUMES_TRAPEZOIDVOLUMESBOUNDS_H
+}
\ No newline at end of file
diff --git a/Core/include/Acts/Volumes/Volume.hpp b/Core/include/Acts/Volumes/Volume.hpp
index e48923435fe8e85a35bd2fd1939a38a3c6abdf6f..cfecd5082ec6e1c336fb5f63b1559e585d35f539 100644
--- a/Core/include/Acts/Volumes/Volume.hpp
+++ b/Core/include/Acts/Volumes/Volume.hpp
@@ -9,9 +9,7 @@
 ///////////////////////////////////////////////////////////////////
 // AbstractVolume.h, ACTS project
 ///////////////////////////////////////////////////////////////////
-#ifndef ACTS_VOLUMES_VOLUME_H
-#define ACTS_VOLUMES_VOLUME_H 1
-
+#pragma once
 #include <memory>
 #include "Acts/Utilities/Definitions.hpp"
 #include "Acts/Utilities/GeometryObject.hpp"
@@ -120,6 +118,4 @@ Volume::volumeBounds() const
 std::ostream&
 operator<<(std::ostream& sl, const Volume& vol);
 
-}  // end of namespace Acts
-
-#endif  // ACTS_VOLUMES_VOLUME_H
+}  // end of namespace Acts
\ No newline at end of file
diff --git a/Core/include/Acts/Volumes/VolumeBounds.hpp b/Core/include/Acts/Volumes/VolumeBounds.hpp
index 8143f2522a803e65af92dd8240cdce728fad9444..f28435baabc0dcebeca6736ec785720ed11147e5 100644
--- a/Core/include/Acts/Volumes/VolumeBounds.hpp
+++ b/Core/include/Acts/Volumes/VolumeBounds.hpp
@@ -10,9 +10,7 @@
 // VolumeBounds.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_VOLUMES_VOLUMEBOUNDS_H
-#define ACTS_VOLUMES_VOLUMEBOUNDS_H 1
-
+#pragma once
 #include <iomanip>
 #include <iostream>
 #include <memory>
@@ -111,6 +109,4 @@ inline double VolumeBounds::binningBorder(BinningValue) const
 std::ostream&
 operator<<(std::ostream& sl, const VolumeBounds& vb);
 
-}  // end of namespace
-
-#endif  // ACTS_VOLUMES_VOLUMEBOUNDS_H
+}  // end of namespace
\ No newline at end of file
diff --git a/IntegrationTests/PropagationTestHelper.hpp b/IntegrationTests/PropagationTestHelper.hpp
index a02d35788c3b933a3c244d786d687c23505b7000..fc43e2acdbbf84a8d364397fa63dbd4db8ca81d8 100644
--- a/IntegrationTests/PropagationTestHelper.hpp
+++ b/IntegrationTests/PropagationTestHelper.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef INTEGRATIONTEST_PROPAGATION_HELPER_H
-#define INTEGRATIONTEST_PROPAGATION_HELPER_H
-
+#pragma once
 #include "covariance_validation_fixture.hpp"
 
 namespace tt = boost::test_tools;
@@ -474,6 +472,4 @@ namespace IntegrationTest {
     }
   }
 }
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/IntegrationTests/covariance_validation_fixture.hpp b/IntegrationTests/covariance_validation_fixture.hpp
index 6a8f4031589f35269a72def0e834253c404556a7..b064f7768b1dbda6daf2b118edd616fd69d6c6cd 100644
--- a/IntegrationTests/covariance_validation_fixture.hpp
+++ b/IntegrationTests/covariance_validation_fixture.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_COVARIANCE_VALIDATION_FIXTURE_HPP
-#define ACTS_COVARIANCE_VALIDATION_FIXTURE_HPP 1
-
+#pragma once
 #include <array>
 #include "Acts/EventData/TrackParameters.hpp"
 #include "Acts/Surfaces/PlaneSurface.hpp"
@@ -155,5 +153,4 @@ namespace IntegrationTest {
 
 }  // namespace Test
 
-}  // namespace Acts
-#endif  // ACTS_COVARIANCE_VALIDATION_FIXTURE_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Legacy/include/Acts/Extrapolation/ExtrapolationCell.hpp b/Legacy/include/Acts/Extrapolation/ExtrapolationCell.hpp
index 968c70d9fce33e07cb9d4d83411d5d689023abc1..254f970d71d5e0a484f391caa9d8a9b0945a5126 100644
--- a/Legacy/include/Acts/Extrapolation/ExtrapolationCell.hpp
+++ b/Legacy/include/Acts/Extrapolation/ExtrapolationCell.hpp
@@ -10,9 +10,7 @@
 // ExtrapolationCell.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_EXTRAPOLATIONUTILS_EXTRAPOLATIONCELL_H
-#define ACTS_EXTRAPOLATIONUTILS_EXTRAPOLATIONCELL_H 1
-
+#pragma once
 #include "Acts/EventData/ParticleDefinitions.hpp"
 #include "Acts/EventData/TransportJacobian.hpp"
 #include "Acts/Extrapolation/MaterialUpdateMode.hpp"
@@ -603,6 +601,4 @@ public:
 };
 }  // end of namespace
 
-#include "Acts/Extrapolation/detail/ExtrapolationCell.ipp"
-
-#endif  // TRKEXUTILS_SOLUTIONSELECTOR_H
+#include "Acts/Extrapolation/detail/ExtrapolationCell.ipp"
\ No newline at end of file
diff --git a/Legacy/include/Acts/Extrapolation/ExtrapolationEngine.hpp b/Legacy/include/Acts/Extrapolation/ExtrapolationEngine.hpp
index f747a110f2787ff89e950b6d5ab282a70b10eae0..8349cdc8b089e60d1d82e867704e5c8df69219dc 100644
--- a/Legacy/include/Acts/Extrapolation/ExtrapolationEngine.hpp
+++ b/Legacy/include/Acts/Extrapolation/ExtrapolationEngine.hpp
@@ -10,9 +10,7 @@
 // ExtrapolationEngine.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_EXTRAPOLATION_EXTRAPOLATIONENGINE_H
-#define ACTS_EXTRAPOLATION_EXTRAPOLATIONENGINE_H 1
-
+#pragma once
 #include "Acts/EventData/NeutralParameters.hpp"
 #include "Acts/EventData/TrackParameters.hpp"
 #include "Acts/Extrapolation/ExtrapolationCell.hpp"
@@ -192,6 +190,4 @@ ExtrapolationEngine::getConfiguration() const
 
 }  // end of namespace
 
-#include "Acts/Extrapolation/detail/ExtrapolationEngine.ipp"
-
-#endif  // ACTS_EXTRAPOLATION_EXTRAPOLATIONENGINE_H
+#include "Acts/Extrapolation/detail/ExtrapolationEngine.ipp"
\ No newline at end of file
diff --git a/Legacy/include/Acts/Extrapolation/IExtrapolationEngine.hpp b/Legacy/include/Acts/Extrapolation/IExtrapolationEngine.hpp
index 38606de1e5758f1a1dbeb5d3f7f5c4fb4e3791bb..147576fc2b2b1333cda36d5b320ebe4ae572efe6 100644
--- a/Legacy/include/Acts/Extrapolation/IExtrapolationEngine.hpp
+++ b/Legacy/include/Acts/Extrapolation/IExtrapolationEngine.hpp
@@ -10,9 +10,7 @@
 // IExtrapolationEngine.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_EXTRAPOLATION_IEXTRAPOLATIONENGINE_H
-#define ACTS_EXTRAPOLATION_IEXTRAPOLATIONENGINE_H 1
-
+#pragma once
 #include "Acts/EventData/NeutralParameters.hpp"
 #include "Acts/EventData/TrackParameters.hpp"
 #include "Acts/Extrapolation/ExtrapolationCell.hpp"
@@ -75,6 +73,4 @@ protected:
   std::string m_sopPostfix;  /// prefix for screen output
 };
 
-}  // end of namespace
-
-#endif  // ACTS_EXTRAPOLATION_IEXTRAPOLATIONENGINE_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Legacy/include/Acts/Extrapolation/IMaterialEffectsEngine.hpp b/Legacy/include/Acts/Extrapolation/IMaterialEffectsEngine.hpp
index 72295f091f9ddb2c76cde4bbc5fa6333b3c052d2..34a2029f300ce5e499f751e064b5b23262d099e1 100644
--- a/Legacy/include/Acts/Extrapolation/IMaterialEffectsEngine.hpp
+++ b/Legacy/include/Acts/Extrapolation/IMaterialEffectsEngine.hpp
@@ -10,9 +10,7 @@
 // IMaterialEffectsEngine.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_EXTRAPOLATION_IMATERIALEFFECTSENGINE_H
-#define ACTS_EXTRAPOLATION_IMATERIALEFFECTSENGINE_H 1
-
+#pragma once
 #include "Acts/EventData/NeutralParameters.hpp"
 #include "Acts/EventData/TrackParameters.hpp"
 #include "Acts/Extrapolation/ExtrapolationCell.hpp"
@@ -71,6 +69,4 @@ protected:
   std::string m_sopPostfix;  ///< prefix for screen output
 };
 
-}  // end of namespace
-
-#endif  // ACTS_EXTRAPOLATION_IMATERIALEFFECTSENGINE_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Legacy/include/Acts/Extrapolation/IMultipleScatteringUpdator.hpp b/Legacy/include/Acts/Extrapolation/IMultipleScatteringUpdator.hpp
index 08c813aa3fd5198f2410692e4205260907947799..d636808e1eacce4aff43dad8a039058323449779 100644
--- a/Legacy/include/Acts/Extrapolation/IMultipleScatteringUpdator.hpp
+++ b/Legacy/include/Acts/Extrapolation/IMultipleScatteringUpdator.hpp
@@ -10,9 +10,7 @@
 // IMultipleScatteringUpdator.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_EXTRAPOLATIONIN_IMULTIPLESCATTERINGUPDATOR_H
-#define ACTS_EXTRAPOLATIONIN_IMULTIPLESCATTERINGUPDATOR_H 1
-
+#pragma once
 #include "Acts/EventData/ParticleDefinitions.hpp"
 
 namespace Acts {
@@ -43,6 +41,4 @@ public:
               double                    deltaE = 0.) const = 0;
 };
 
-}  // end of namespace
-
-#endif  // ACTS_EXTRAPOLATIONIN_IMULTIPLESCATTERINGUPDATOR_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Legacy/include/Acts/Extrapolation/INavigationEngine.hpp b/Legacy/include/Acts/Extrapolation/INavigationEngine.hpp
index b900d2c2ae683dacb4a85f5dc0eb1f62ec11384d..3f6cd15260040ec0c8d5f2edd13715f2a011e7f7 100644
--- a/Legacy/include/Acts/Extrapolation/INavigationEngine.hpp
+++ b/Legacy/include/Acts/Extrapolation/INavigationEngine.hpp
@@ -10,9 +10,7 @@
 // INavigationEngine.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_EXTRAPOLATION_INAVIGATIONENGINE_H
-#define ACTS_EXTRAPOLATION_INAVIGATIONENGINE_H
-
+#pragma once
 #include "Acts/EventData/NeutralParameters.hpp"
 #include "Acts/EventData/TrackParameters.hpp"
 #include "Acts/Extrapolation/ExtrapolationCell.hpp"
@@ -86,6 +84,4 @@ protected:
   std::string m_sopPostfix;  ///< prefix for screen output
 };
 
-}  // end of namespace
-
-#endif  // ACTS_EXTRAPOLATION_INAVIGATIONENGINE_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Legacy/include/Acts/Extrapolation/IPropagationEngine.hpp b/Legacy/include/Acts/Extrapolation/IPropagationEngine.hpp
index f334833fc798fb588d6b501cdf4653b13396a0c9..7d015d0d02f0263cc3621bc994efd4077fd5430a 100644
--- a/Legacy/include/Acts/Extrapolation/IPropagationEngine.hpp
+++ b/Legacy/include/Acts/Extrapolation/IPropagationEngine.hpp
@@ -10,9 +10,7 @@
 // IPropagationEngine.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_EXTRAPOLATION_IPROPAGATIONENGINE_H
-#define ACTS_EXTRAPOLATION_IPROPAGATIONENGINE_H 1
-
+#pragma once
 #include "Acts/EventData/NeutralParameters.hpp"
 #include "Acts/EventData/TrackParameters.hpp"
 #include "Acts/Extrapolation/ExtrapolationCell.hpp"
@@ -92,6 +90,4 @@ protected:
   std::string m_sopPostfix;  ///< prefix for screen output
 };
 
-}  // end of namespace
-
-#endif  // ACTS_EXTRAPOLATION_IPROPAGATIONENGINE_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Legacy/include/Acts/Extrapolation/MaterialEffectsEngine.hpp b/Legacy/include/Acts/Extrapolation/MaterialEffectsEngine.hpp
index 4e46188c68a3243fd356de4333fefd411130e2bf..941a249505dfa609f612dab910eeb8dd37a473ef 100644
--- a/Legacy/include/Acts/Extrapolation/MaterialEffectsEngine.hpp
+++ b/Legacy/include/Acts/Extrapolation/MaterialEffectsEngine.hpp
@@ -10,9 +10,7 @@
 // MaterialEffectsEngine.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_EXTRAPOLATION_MATERIALEFFECTSENGINE_H
-#define ACTS_EXTRAPOLATION_MATERIALEFFECTSENGINE_H 1
-
+#pragma once
 #include "Acts/EventData/NeutralParameters.hpp"
 #include "Acts/EventData/TrackParameters.hpp"
 #include "Acts/Extrapolation/ExtrapolationCell.hpp"
@@ -155,6 +153,4 @@ MaterialEffectsEngine::getConfiguration() const
   return m_cfg;
 }
 
-}  // end of namespace
-
-#endif  // ACTS_EXTRAPOLATION_MATERIALEFFECTSENGINE_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Legacy/include/Acts/Extrapolation/MaterialUpdateMode.hpp b/Legacy/include/Acts/Extrapolation/MaterialUpdateMode.hpp
index 225a21c6eeb6ba3f530ebcca9c65ff602562df21..9c942aa4c5e1a15ccbadf23a2c2c0d0bb36eb5e3 100644
--- a/Legacy/include/Acts/Extrapolation/MaterialUpdateMode.hpp
+++ b/Legacy/include/Acts/Extrapolation/MaterialUpdateMode.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_EXTRAPOLATIONUTILS_MATERIALUPDATEMODE_H
-#define ACTS_EXTRAPOLATIONUTILS_MATERIALUPDATEMODE_H 1
-
+#pragma once
 namespace Acts {
 
 /// This is a steering enum to force the material update
@@ -18,6 +16,4 @@ namespace Acts {
 /// Second is mainly for vertex reconstruction, but potentially dangeraous.
 
 enum MaterialUpdateMode { addNoise = 1, removeNoise = -1 };
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/Legacy/include/Acts/Extrapolation/RungeKuttaEngine.hpp b/Legacy/include/Acts/Extrapolation/RungeKuttaEngine.hpp
index 299b3c9d218a986e6a6d3e093ed0627b46d2b967..1e84509efa534ef6fe01c8279df5b6a86607d7d0 100644
--- a/Legacy/include/Acts/Extrapolation/RungeKuttaEngine.hpp
+++ b/Legacy/include/Acts/Extrapolation/RungeKuttaEngine.hpp
@@ -10,9 +10,7 @@
 //  Header file for class RungeKuttaEngine, ACTS project
 /////////////////////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_EXTRAPOLATION_RUNGEKUTAENGINE_H
-#define ACTS_EXTRAPOLATION_RUNGEKUTAENGINE_H 1
-
+#pragma once
 #include "Acts/EventData/NeutralParameters.hpp"
 #include "Acts/EventData/TrackParameters.hpp"
 #include "Acts/Extrapolation/ExtrapolationCell.hpp"
@@ -385,6 +383,4 @@ private:
 ////////////////////////////////////////////////////////////////////////////////
 // Templated method
 ////////////////////////////////////////////////////////////////////////////////
-#include "Acts/Extrapolation/detail/RungeKuttaEngine.ipp"
-
-#endif  // ACTS_EXTRAPOLATION_RUNGEKUTAENGINE_H
+#include "Acts/Extrapolation/detail/RungeKuttaEngine.ipp"
\ No newline at end of file
diff --git a/Legacy/include/Acts/Extrapolation/StaticEngine.hpp b/Legacy/include/Acts/Extrapolation/StaticEngine.hpp
index 4051551cbcb5a7da20d5968159ce9e556ceebe6b..570a8d0710c21ec2310a7bbbf1e004270d242018 100644
--- a/Legacy/include/Acts/Extrapolation/StaticEngine.hpp
+++ b/Legacy/include/Acts/Extrapolation/StaticEngine.hpp
@@ -10,9 +10,7 @@
 // StaticEngine.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_EXTRAPOLATION_STATICENGINE_H
-#define ACTS_EXTRAPOLATION_STATICENGINE_H 1
-
+#pragma once
 #ifndef ACTS_EXTRAPOLATION_OUTPUTHELPER
 #define ACTS_EXTRAPOLATION_OUTPUTHELPER 1
 #define OH_CHECKFOUND(object) (object ? "found" : "not found")
@@ -240,6 +238,4 @@ StaticEngine::getConfiguration() const
 
 }  // end of namespace
 
-#include "Acts/Extrapolation/detail/StaticEngine.ipp"
-
-#endif  // ACTS_EXTRAPOLATION_STATICENGINE_H
+#include "Acts/Extrapolation/detail/StaticEngine.ipp"
\ No newline at end of file
diff --git a/Legacy/include/Acts/Extrapolation/StaticNavigationEngine.hpp b/Legacy/include/Acts/Extrapolation/StaticNavigationEngine.hpp
index b5802590f9f9a9398e777758ccd8a2bc339a76a1..0c846048708d26b44753838ab17801c4a67febdb 100644
--- a/Legacy/include/Acts/Extrapolation/StaticNavigationEngine.hpp
+++ b/Legacy/include/Acts/Extrapolation/StaticNavigationEngine.hpp
@@ -10,9 +10,7 @@
 // StaticNavigationEngine.h, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_EXTRAPOLATION_STATICNAVIGATIONENGINE_H
-#define ACTS_EXTRAPOLATION_STATICNAVIGATIONENGINE_H 1
-
+#pragma once
 #include "Acts/EventData/NeutralParameters.hpp"
 #include "Acts/EventData/TrackParameters.hpp"
 #include "Acts/Extrapolation/ExtrapolationCell.hpp"
@@ -192,6 +190,4 @@ StaticNavigationEngine::getConfiguration() const
 
 }  // end of namespace
 
-#include "Acts/Extrapolation/detail/StaticNavigationEngine.ipp"
-
-#endif  // ACTS_EXTRAPOLATION_STATICNAVIGATIONENGINE_H
+#include "Acts/Extrapolation/detail/StaticNavigationEngine.ipp"
\ No newline at end of file
diff --git a/Legacy/include/Acts/Extrapolation/Wrapper.hpp b/Legacy/include/Acts/Extrapolation/Wrapper.hpp
index 24ee83d24f8e0880a00d842ef4483ed5a9904fbe..6dc6e1f2d62ddbeb150dcd9bb3eaa3b6e2c41321 100644
--- a/Legacy/include/Acts/Extrapolation/Wrapper.hpp
+++ b/Legacy/include/Acts/Extrapolation/Wrapper.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_EXTRAPOLATION_WRAPPER_H
-#define ACTS_EXTRAPOLATION_WRAPPER_H
-
+#pragma once
 #include <cmath>
 #include <limits>
 #include <memory>
@@ -277,6 +275,4 @@ namespace propagation {
 
 }  // namespace propagation
 
-}  // namespace Acts
-
-#endif  // ACTS_EXTRAPOLATION_WRAPPER_H
+}  // namespace Acts
\ No newline at end of file
diff --git a/Legacy/include/Acts/Extrapolation/detail/ExtrapolationMacros.hpp b/Legacy/include/Acts/Extrapolation/detail/ExtrapolationMacros.hpp
index 9a9545c4e132a172e6e640524b4762a9f94e92c7..c8dacf5bb07477220eda3aacf5e9e23e3bd69a27 100644
--- a/Legacy/include/Acts/Extrapolation/detail/ExtrapolationMacros.hpp
+++ b/Legacy/include/Acts/Extrapolation/detail/ExtrapolationMacros.hpp
@@ -11,8 +11,8 @@
 ///////////////////////////////////////////////////////////////////
 // output stream macros to facilitate screen output and consistent checking
 
-#ifndef EXSCREENOUTPUTDEFS
-#define EXSCREENOUTPUTDEFS 1
+#pragma once
+
 #define EX_MSG_INFO(navstep, step, idx, x)                                     \
   ACTS_INFO(m_sopPrefix << std::setw(4) << navstep << m_sopPostfix             \
                         << std::setw(12)                                       \
@@ -58,15 +58,9 @@
                          << idx                                                \
                          << m_sopPostfix                                       \
                          << x)
-#endif
 
-#ifndef EXENINGE_OUTPUTHELPER
-#define TRKEXENINGE_OUTPUTHELPER 1
 #define OH_CHECKFOUND(object) (object ? "found" : "not found")
-#endif
 
-#ifndef EXENGINE_EXCODECHECKS
-#define TRKEXENGINE_EXCODECHECKS 1
 #define CHECK_ECODE_CONTINUE(ecell, ecode)                                     \
   if (!ecode.inProgress()) {                                                   \
     EX_MSG_VERBOSE(ecell.navigationStep,                                       \
@@ -91,4 +85,3 @@
                    ecode.toString() << " stops extrapolation sequence.");      \
     return ecode;                                                              \
   }
-#endif
diff --git a/Legacy/include/Acts/Extrapolation/detail/RungeKuttaUtils.hpp b/Legacy/include/Acts/Extrapolation/detail/RungeKuttaUtils.hpp
index 71b742f4b71c6a9a83b2368b9fc0b2e8610e501d..2005d05d0c124becfb5c5a8e2e0e1752c5ef1b85 100644
--- a/Legacy/include/Acts/Extrapolation/detail/RungeKuttaUtils.hpp
+++ b/Legacy/include/Acts/Extrapolation/detail/RungeKuttaUtils.hpp
@@ -10,9 +10,7 @@
 //  RungeKuttaUtils.h, ACTS project
 /////////////////////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_EXTRAPOLATIONDETAILS_RUNGEKUTTAUTILS_H
-#define ACTS_EXTRAPOLATIONDETAILS_RUNGEKUTTAUTILS_H 1
-
+#pragma once
 #include <limits>
 #include <map>
 #include <vector>
@@ -212,6 +210,4 @@ private:
   bool
   transformLocalToGlobal(bool, const Surface*, const double*, double*) const;
 };
-}  // end of namespace
-
-#endif  // ACTS_EXTRAPOLATIONDETAILS_RUNGEKUTTAUTILS_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Legacy/include/Acts/Propagator/AtlasStepper.hpp b/Legacy/include/Acts/Propagator/AtlasStepper.hpp
index 1e0a6161697e6a28c841e4be240c5fa95a76b7e6..31389aa7c6bdf415b567c1d4f75c5a217826233b 100644
--- a/Legacy/include/Acts/Propagator/AtlasStepper.hpp
+++ b/Legacy/include/Acts/Propagator/AtlasStepper.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_ATLAS_STEPPER_HPP
-#define ACTS_ATLAS_STEPPER_HPP
-
+#pragma once
 #include <cmath>
 #include "Acts/EventData/TrackParameters.hpp"
 #include "Acts/MagneticField/concept/AnyFieldLookup.hpp"
@@ -894,5 +892,4 @@ private:
   BField m_bField;
 };
 
-}  // namespace Acts
-#endif  // ACTS_ATLAS_STEPPER_HPP
+}  // namespace Acts
\ No newline at end of file
diff --git a/Legacy/include/Acts/Seeding/ATL_Seedmaker.hpp b/Legacy/include/Acts/Seeding/ATL_Seedmaker.hpp
index 71dbf305710073c0e39fe73860f18ca70f982ee0..3523b5950890e21c929baf4249019bd0a7d6d309 100644
--- a/Legacy/include/Acts/Seeding/ATL_Seedmaker.hpp
+++ b/Legacy/include/Acts/Seeding/ATL_Seedmaker.hpp
@@ -10,9 +10,7 @@
 // ATL_Seedmaker.hpp ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ATL_Seedmaker_hpp
-#define ATL_Seedmaker_hpp
-
+#pragma once
 #include <list>
 #include <map>
 #include <set>
@@ -331,6 +329,4 @@ namespace Seeding {
   };
 }  // end of Seeding namespace
 }  // end of Acts namespace
-#include "Acts/Seeding/ATL_Seedmaker.ipp"
-
-#endif  // ATL_Seedmaker_hpp
+#include "Acts/Seeding/ATL_Seedmaker.ipp"
\ No newline at end of file
diff --git a/Legacy/include/Acts/Seeding/InternalSeed.hpp b/Legacy/include/Acts/Seeding/InternalSeed.hpp
index 1d76b2643316c538abc7b3d49d27ce5db2b9dadb..d56d76bac359eb6822995fa8003d0b61a1a6fd36 100644
--- a/Legacy/include/Acts/Seeding/InternalSeed.hpp
+++ b/Legacy/include/Acts/Seeding/InternalSeed.hpp
@@ -10,9 +10,7 @@
 // InternalSeed.hpp ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef InternalSeed_h
-#define InternalSeed_h
-
+#pragma once
 #include "Acts/Seeding/SPForSeed.hpp"
 #include "Acts/Seeding/Seed.hpp"
 
@@ -212,6 +210,4 @@ namespace Seeding {
   }
 
 }  // end of Seeding namespace
-}  // end of Acts namespace
-
-#endif  // InternalSeed_h
+}  // end of Acts namespace
\ No newline at end of file
diff --git a/Legacy/include/Acts/Seeding/SPForSeed.hpp b/Legacy/include/Acts/Seeding/SPForSeed.hpp
index ce21b86dbb32666bd5fbb09ed86d6df8cc0095e6..91d3ab353e8c91238c582d1b7d44968277947d82 100644
--- a/Legacy/include/Acts/Seeding/SPForSeed.hpp
+++ b/Legacy/include/Acts/Seeding/SPForSeed.hpp
@@ -10,9 +10,7 @@
 // SPForSeed.hpp ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef SPForSeed_hpp
-#define SPForSeed_hpp
-
+#pragma once
 #include <cmath>
 
 // COLLECTION OF MAGIC NUMBERS IN HERE:
@@ -296,6 +294,4 @@ namespace Seeding {
   }
 
 }  // end of Seeding namespace
-}  // end of Acts namespace
-
-#endif  // SPForSeed_hpp
+}  // end of Acts namespace
\ No newline at end of file
diff --git a/Legacy/include/Acts/Seeding/Seed.hpp b/Legacy/include/Acts/Seeding/Seed.hpp
index 42261391b4aceb844af965a88da4a4a0fc3d06df..2dfbbcb5e581f65e71b56f02d826d083d6b91db6 100644
--- a/Legacy/include/Acts/Seeding/Seed.hpp
+++ b/Legacy/include/Acts/Seeding/Seed.hpp
@@ -10,8 +10,7 @@
 // Seed.hpp ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef Seed_h
-#define Seed_h
+#pragma once
 #include <list>
 
 namespace Acts {
@@ -133,6 +132,4 @@ namespace Seeding {
   {
   }
 }  // end of Seeding namespace
-}  // end of Acts namespace
-
-#endif  // Seed_h
+}  // end of Acts namespace
\ No newline at end of file
diff --git a/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/ActsExtension.hpp b/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/ActsExtension.hpp
index 63d0eede0a1189c141036d26ec187500cf10dd07..f8487cd18b50816d9a6beed620fb27997442628a 100644
--- a/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/ActsExtension.hpp
+++ b/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/ActsExtension.hpp
@@ -10,14 +10,13 @@
 // ActsExtension.h, ACTS project, DD4hepDetector plugin
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_DD4HEPDETECTORELEMENT_ACTSEXTENSION_H
-#define ACTS_DD4HEPDETECTORELEMENT_ACTSEXTENSION_H 1
+#pragma once
 
-#include "Acts/Plugins/DD4hepPlugins/IActsExtension.hpp"
 #include <vector>
 #include "Acts/Digitization/CartesianSegmentation.hpp"
 #include "Acts/Digitization/DigitizationModule.hpp"
 #include "Acts/Material/SurfaceMaterial.hpp"
+#include "Acts/Plugins/DD4hepPlugins/IActsExtension.hpp"
 #include "Acts/Surfaces/RectangleBounds.hpp"
 #include "DD4hep/CartesianGridXY.h"
 #include "DD4hep/Detector.h"
@@ -452,5 +451,3 @@ Acts::ActsExtension::material() const
   return m_material;
 }
 }
-
-#endif  // ACTS_DD4HEPDETECTORELEMENT_ACTSEXTENSION_H
diff --git a/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/ConvertDD4hepDetector.hpp b/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/ConvertDD4hepDetector.hpp
index 6f84834a5718028e5293cf6afd0a7da79aca5378..a7c102de55d390625a5c2b2ba1fea8b7c4f69256 100644
--- a/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/ConvertDD4hepDetector.hpp
+++ b/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/ConvertDD4hepDetector.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_DD4HEPPLUGIN_CONVERTDD4HEPDETECTOR_H
-#define ACTS_DD4HEPPLUGIN_CONVERTDD4HEPDETECTOR_H 1
-
+#pragma once
 #include "Acts/Detector/TrackingGeometry.hpp"
 #include "Acts/Tools/CylinderVolumeBuilder.hpp"
 #include "Acts/Tools/CylinderVolumeHelper.hpp"
@@ -202,6 +200,4 @@ collectCompounds_dd4hep(dd4hep::DetElement&              detElement,
 void
 collectLayers_dd4hep(dd4hep::DetElement&              detElement,
                      std::vector<dd4hep::DetElement>& layers);
-}
-
-#endif  // ACTS_DD4HEPPLUGIN_CONVERTDD4HEPDETECTOR_H
+}
\ No newline at end of file
diff --git a/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/DD4hepDetElement.hpp b/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/DD4hepDetElement.hpp
index aa1c76d1f0b3eae969f475fbb22544be1c01b693..9948066025ddfb9c476ab8fd32367c8e134d2969 100644
--- a/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/DD4hepDetElement.hpp
+++ b/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/DD4hepDetElement.hpp
@@ -10,9 +10,7 @@
 // DD4hepDetElement.h, ACTS project, DD4hepDetector plugin
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_DD4HEPDETECTORELEMENT_DD4HEPDETELEMENT_H
-#define ACTS_DD4HEPDETECTORELEMENT_DD4HEPDETELEMENT_H 1
-
+#pragma once
 #include "Acts/Plugins/TGeoPlugins/TGeoDetectorElement.hpp"
 #include "DD4hep/DetElement.h"
 
@@ -107,6 +105,4 @@ private:
   /// The DigitizationModule
   std::shared_ptr<const DigitizationModule> m_digiModule;
 };
-}
-
-#endif  // ACTS_DD4HEPDETECTORELEMENT_DD4HEPDETELEMENT_H
+}
\ No newline at end of file
diff --git a/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/DD4hepLayerBuilder.hpp b/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/DD4hepLayerBuilder.hpp
index 3505cdce25deaad3bbf9444e116bd16510c19372..568e40b40609ab8d258fc1f5a121640e4c149bc1 100644
--- a/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/DD4hepLayerBuilder.hpp
+++ b/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/DD4hepLayerBuilder.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_DD4HEPPLUGIN_DD4HEPLAYERBUILDER_H
-#define ACTS_DD4HEPPLUGIN_DD4HEPLAYERBUILDER_H 1
-
+#pragma once
 #include "Acts/Surfaces/Surface.hpp"
 #include "Acts/Tools/ILayerBuilder.hpp"
 #include "Acts/Tools/LayerCreator.hpp"
@@ -182,6 +180,4 @@ DD4hepLayerBuilder::getConfiguration() const
   return m_cfg;
 }
 
-}  // end of namespace
-
-#endif  // ACTS_DD4HEPPLUGIN_DD4HEPLAYERBUILDER_H
+}  // end of namespace
\ No newline at end of file
diff --git a/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/IActsExtension.hpp b/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/IActsExtension.hpp
index 26382b9587513e81a6474a6fa63237fe8ae8aeb2..43fc9f0417589a8e2e480793bc9601f2aea2c4a4 100644
--- a/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/IActsExtension.hpp
+++ b/Plugins/DD4hepPlugin/include/Acts/Plugins/DD4hepPlugins/IActsExtension.hpp
@@ -10,9 +10,7 @@
 // IDetExtension.h, ACTS project, DD4hepDetector plugin
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_DD4HEPDETECTORELEMENT_IACTSEXTENSION_H
-#define ACTS_DD4HEPDETECTORELEMENT_IACTSEXTENSION_H 1
-
+#pragma once
 // Algebra
 #include <memory>
 #include <vector>
@@ -147,6 +145,4 @@ protected:
   /// Protected constructor
   IActsExtension() {}
 };
-}
-
-#endif  // ACTS_DD4HEPDETECTORELEMENT_DET_IACTSEXTENSION_H
+}
\ No newline at end of file
diff --git a/Plugins/Geant4Plugin/include/Acts/Plugins/Geant4Plugins/Geant4DetectorElement.hpp b/Plugins/Geant4Plugin/include/Acts/Plugins/Geant4Plugins/Geant4DetectorElement.hpp
index 00dccd436b9136528077d1edfa7fd21ca2afb592..2536f104813dd3394b7f6024f10d24c72f403383 100644
--- a/Plugins/Geant4Plugin/include/Acts/Plugins/Geant4Plugins/Geant4DetectorElement.hpp
+++ b/Plugins/Geant4Plugin/include/Acts/Plugins/Geant4Plugins/Geant4DetectorElement.hpp
@@ -10,9 +10,7 @@
 // Geant4DetElement.h, ACTS project, DD4hepDetector plugin
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_GEANT4PLUGINS_GEANT4DETECTORELEMENT_H
-#define ACTS_GEANT4PLUGINS_GEANT4DETECTORELEMENT_H 1
-
+#pragma once
 namespace Acts {
 
 /** @class Geant4DetElement
@@ -29,6 +27,4 @@ public:
 
 private:
 };
-}
-
-#endif  // ACTS_GEANT4PLUGINS_GEANT4DETECTORELEMENT_H
+}
\ No newline at end of file
diff --git a/Plugins/JsonPlugin/include/Acts/Plugins/JsonPlugin/FromJson.hpp b/Plugins/JsonPlugin/include/Acts/Plugins/JsonPlugin/FromJson.hpp
index e33fdbe4e0d06d80298649394ab33b50cf32edff..f704f6d16a4d77794e9c1d3903c5e367513fdd97 100644
--- a/Plugins/JsonPlugin/include/Acts/Plugins/JsonPlugin/FromJson.hpp
+++ b/Plugins/JsonPlugin/include/Acts/Plugins/JsonPlugin/FromJson.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_PLUGINS_JSONPLUGIN_JSONLOADER_H
-#define ACTS_PLUGINS_JSONPLUGIN_JSONLOADER_H
-
+#pragma once
 #include "Acts/Utilities/VariantDataFwd.hpp"
 #include "lib/json.hpp"
 
@@ -21,6 +19,4 @@ namespace Acts {
 variant_data
 from_json(const nlohmann::json& node);
 
-}  // namespace Acts
-
-#endif
+}  // namespace Acts
\ No newline at end of file
diff --git a/Plugins/JsonPlugin/include/Acts/Plugins/JsonPlugin/lib/json.hpp b/Plugins/JsonPlugin/include/Acts/Plugins/JsonPlugin/lib/json.hpp
index 5b0b0ea5b3018dd2562e1ac7df6d76b3b8e2cde6..f7d9fb3879f8991989c5c2152480093add030159 100644
--- a/Plugins/JsonPlugin/include/Acts/Plugins/JsonPlugin/lib/json.hpp
+++ b/Plugins/JsonPlugin/include/Acts/Plugins/JsonPlugin/lib/json.hpp
@@ -26,9 +26,7 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE  OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 */
 
-#ifndef NLOHMANN_JSON_HPP
-#define NLOHMANN_JSON_HPP
-
+#pragma once
 #include <algorithm> // all_of, copy, fill, find, for_each, generate_n, none_of, remove, reverse, transform
 #include <array> // array
 #include <cassert> // assert
@@ -14869,6 +14867,4 @@ inline nlohmann::json::json_pointer operator "" _json_pointer(const char* s, std
 #undef JSON_UNLIKELY
 #undef JSON_DEPRECATED
 #undef NLOHMANN_BASIC_JSON_TPL_DECLARATION
-#undef NLOHMANN_BASIC_JSON_TPL
-
-#endif
+#undef NLOHMANN_BASIC_JSON_TPL
\ No newline at end of file
diff --git a/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/AssignedMaterialSteps.hpp b/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/AssignedMaterialSteps.hpp
index 1d3b4c063f571ce9a92ace2c929f2e19ebedac31..ff9da717a9b25626b75dcb512dc7ff4c131fd60a 100644
--- a/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/AssignedMaterialSteps.hpp
+++ b/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/AssignedMaterialSteps.hpp
@@ -10,9 +10,7 @@
 // AssignedMaterialSteps.h, ACTS project MaterialPlugins
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_MATERIALPLUGINS_ASSIGNEDMATERIALSTEPS_H
-#define ACTS_MATERIALPLUGINS_ASSIGNEDMATERIALSTEPS_H
-
+#pragma once
 #include "Acts/Plugins/MaterialPlugins/MaterialStep.hpp"
 #include "Acts/Utilities/Definitions.hpp"
 #include "Acts/Utilities/GeometryID.hpp"
@@ -36,6 +34,4 @@ struct AssignedMaterialSteps
   {
   }
 };
-}
-
-#endif  // ACTS_MATERIALPLUGINS_ASSIGNEDMATERIALSTEPS_H
+}
\ No newline at end of file
diff --git a/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/MaterialMapper.hpp b/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/MaterialMapper.hpp
index 83f03898b45699ee3265df13949e75a098855211..a574d637d82ed9a69737d8c028f0c87c8f8bb1db 100644
--- a/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/MaterialMapper.hpp
+++ b/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/MaterialMapper.hpp
@@ -10,9 +10,7 @@
 // MaterialMapper.h, ACTS project MaterialPlugins
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_MATERIALPLUGINS_MATERIALMAPPER_H
-#define ACTS_MATERIALPLUGINS_MATERIALMAPPER_H
-
+#pragma once
 #include <map>
 #include <utility>
 #include "Acts/Extrapolation/IExtrapolationEngine.hpp"
@@ -182,6 +180,4 @@ private:
   /// the logging instance
   std::unique_ptr<const Logger> m_logger;
 };
-}
-
-#endif  // ACTS_MATERIALPLUGINS_MATERIALMAPPING_H
+}
\ No newline at end of file
diff --git a/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/MaterialStep.hpp b/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/MaterialStep.hpp
index e7edbf1a5eb4c28348ccee28283b6881cf90c57a..e80d394b31a36fadaeba72620ef2fdb99de87419 100644
--- a/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/MaterialStep.hpp
+++ b/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/MaterialStep.hpp
@@ -10,9 +10,7 @@
 // MaterialStep.hpp, ACTS project
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_MATERIALPLUGINS_MATERIALSTEP_H
-#define ACTS_MATERIALPLUGINS_MATERIALSTEP_H
-
+#pragma once
 #include <memory>
 #include "Acts/Material/MaterialProperties.hpp"
 
@@ -154,6 +152,4 @@ inline uint64_t
 Acts::MaterialStep::geoID() const
 {
   return m_geoID;
-}
-
-#endif  // ACTS_MATERIALPLUGINS_MATERIALSTEP_H
+}
\ No newline at end of file
diff --git a/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/MaterialTrack.hpp b/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/MaterialTrack.hpp
index bbd77abb1e0fb380f8dfcd16b40b69b83932fd32..4e1a77a83e2a417d66d35230c638ea0501d6a84b 100644
--- a/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/MaterialTrack.hpp
+++ b/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/MaterialTrack.hpp
@@ -10,9 +10,7 @@
 // MaterialTrack.hpp, ACTS project MaterialPlugins
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_MATERIALPLUGINS_MATERIALTRACK_H
-#define ACTS_MATERIALPLUGINS_MATERIALTRACK_H
-
+#pragma once
 #include <vector>
 #include "Acts/Plugins/MaterialPlugins/MaterialStep.hpp"
 
@@ -155,6 +153,4 @@ inline std::vector<Acts::MaterialStep>
 Acts::MaterialTrack::materialSteps() const
 {
   return m_materialSteps;
-}
-
-#endif  // ACTS_MATERIALPLUGINS_MATERIALTRACK_H
+}
\ No newline at end of file
diff --git a/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/SurfaceMaterialRecord.hpp b/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/SurfaceMaterialRecord.hpp
index 42e581b09cbb890862ff27c17d4cae872740e2f3..2317ecc83dfbcd213db3d161e4dbe63e72352e2f 100644
--- a/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/SurfaceMaterialRecord.hpp
+++ b/Plugins/MaterialPlugin/include/Acts/Plugins/MaterialPlugins/SurfaceMaterialRecord.hpp
@@ -10,9 +10,7 @@
 // SurfaceMaterialRecord.h, ACTS project MaterialPlugins
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_MATERIALPLUGINS_SURFACEMATERIALRECORD_H
-#define ACTS_MATERIALPLUGINS_SURFACEMATERIALRECORD_H
-
+#pragma once
 #include "Acts/Material/BinnedSurfaceMaterial.hpp"
 #include "Acts/Material/MaterialProperties.hpp"
 #include "Acts/Plugins/MaterialPlugins/AssignedMaterialSteps.hpp"
@@ -130,6 +128,4 @@ SurfaceMaterialRecord::mappedMaterial() const
 {
   return m_mappedMaterial;
 }
-}
-
-#endif  // ACTS_MATERIALPLUGINS_SURFACEMATERIALRECORD_H
+}
\ No newline at end of file
diff --git a/Plugins/TGeoPlugin/include/Acts/Plugins/TGeoPlugins/TGeoDetectorElement.hpp b/Plugins/TGeoPlugin/include/Acts/Plugins/TGeoPlugins/TGeoDetectorElement.hpp
index d31168a44fd54fa5f4b57613ed23bd26d909db19..dc86905d8d85d215f8c62349f5316a1c2a6dba0a 100644
--- a/Plugins/TGeoPlugin/include/Acts/Plugins/TGeoPlugins/TGeoDetectorElement.hpp
+++ b/Plugins/TGeoPlugin/include/Acts/Plugins/TGeoPlugins/TGeoDetectorElement.hpp
@@ -10,9 +10,7 @@
 // TGeoDetectorElement.h, ACTS project, TGeoDetector plugin
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_TGEODETECTORELEMENT_TGEODETECTORELEMENT
-#define ACTS_TGEODETECTORELEMENT_TGEODETECTORELEMENT 1
-
+#pragma once
 #include <iostream>
 #include "Acts/Detector/DetectorElementBase.hpp"
 #include "TGeoManager.h"
@@ -205,6 +203,4 @@ TGeoDetectorElement::thickness() const
 {
   return m_thickness;
 }
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/Plugins/TGeoPlugin/include/Acts/Plugins/TGeoPlugins/TGeoLayerBuilder.hpp b/Plugins/TGeoPlugin/include/Acts/Plugins/TGeoPlugins/TGeoLayerBuilder.hpp
index ec9d680d96453fc5049efede47afaab3be563166..7df4daf867cd6da5df9a6f4a37507897ed030aae 100644
--- a/Plugins/TGeoPlugin/include/Acts/Plugins/TGeoPlugins/TGeoLayerBuilder.hpp
+++ b/Plugins/TGeoPlugin/include/Acts/Plugins/TGeoPlugins/TGeoLayerBuilder.hpp
@@ -10,9 +10,7 @@
 // TGeoLayerBuilder.h, ACTS project, TGeoDetector plugin
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_TGEOPLUGINS_TGEOLAYERBUILDER_H
-#define ACTS_TGEOPLUGINS_TGEOLAYERBUILDER_H
-
+#pragma once
 #include "Acts/Tools/ILayerBuilder.hpp"
 #include "Acts/Tools/LayerCreator.hpp"
 #include "Acts/Utilities/Definitions.hpp"
@@ -165,6 +163,4 @@ TGeoLayerBuilder::identification() const
 {
   return m_cfg.configurationName;
 }
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/Tests/EventData/ParametersTestHelper.hpp b/Tests/EventData/ParametersTestHelper.hpp
index b5acc2acf8689b5419366a2a9e5f63b4f17c3ab1..1f4c8162da86c8bf46dbb355ac0543149787e231 100644
--- a/Tests/EventData/ParametersTestHelper.hpp
+++ b/Tests/EventData/ParametersTestHelper.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_TESTS_EVENTDATA_PARAMETERTESTHELPER_H
-#define ACTS_TESTS_EVENTDATA_PARAMETERTESTHELPER_H
-
+#pragma once
 #include <boost/test/included/unit_test.hpp>
 #include "Acts/Utilities/Definitions.hpp"
 
@@ -38,6 +36,4 @@ namespace Test {
     BOOST_CHECK_EQUAL(pars.charge(), charge);
   }
 }
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/Tests/Fitter/KalmanFilterTestUtils.hpp b/Tests/Fitter/KalmanFilterTestUtils.hpp
index d3cadb14a07f53d7bc4a96a50df4d100f117e07d..6e68bff286cf1f1049f9979cf415a98643220a19 100644
--- a/Tests/Fitter/KalmanFilterTestUtils.hpp
+++ b/Tests/Fitter/KalmanFilterTestUtils.hpp
@@ -6,9 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_KALMANFITUTILS_H
-#define ACTS_KALMANFITUTILS_H
-
+#pragma once
 #include <cmath>
 #include <fstream>
 #include <iostream>
@@ -151,6 +149,4 @@ initExtrapolator(const std::shared_ptr<const TrackingGeometry>& geo)
   exEngine->setLogger(getDefaultLogger("ExtrapolationEngine", Logging::INFO));
 
   return exEngine;
-};
-
-#endif
+};
\ No newline at end of file
diff --git a/Tests/Layers/LayerStub.hpp b/Tests/Layers/LayerStub.hpp
index a026714c879eb3e992a7310a5868648290ba2e84..d203b069dfb512ad0fac166aba75ec66f0d958fb 100644
--- a/Tests/Layers/LayerStub.hpp
+++ b/Tests/Layers/LayerStub.hpp
@@ -5,9 +5,7 @@
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
-#ifndef ACTS_TEST_LAYERSTUB
-#define ACTS_TEST_LAYERSTUB 1
-
+#pragma once
 #include "../Surfaces/SurfaceStub.hpp"
 #include "Acts/Layers/Layer.hpp"
 
@@ -65,5 +63,4 @@ public:
   /// Other methods have implementation in baseclass
   /// templated 'onLayer()' from baseclass ?
 };
-}
-#endif
+}
\ No newline at end of file
diff --git a/Tests/Surfaces/DetectorElementStub.hpp b/Tests/Surfaces/DetectorElementStub.hpp
index 613b7a462f6f6f35952b307cbe4a48a9c31b2089..fae56002414b45cb073744354d03edf93ca4671e 100644
--- a/Tests/Surfaces/DetectorElementStub.hpp
+++ b/Tests/Surfaces/DetectorElementStub.hpp
@@ -10,9 +10,7 @@
 // DetectorElementStub.h, ACTS project, Generic Detector plugin
 ///////////////////////////////////////////////////////////////////
 
-#ifndef ACTS_TEST_DetectorElementStub_DetectorElementStub
-#define ACTS_TEST_DetectorElementStub_DetectorElementStub 1
-
+#pragma once
 // Algebra and Identifier
 #include "Acts/Utilities/Definitions.hpp"
 #include "Acts/Utilities/Identifier.hpp"
@@ -192,6 +190,4 @@ DetectorElementStub::thickness() const
   return m_elementThickness;
 }
 
-}  // end of ns
-
-#endif
+}  // end of ns
\ No newline at end of file
diff --git a/Tests/Surfaces/LineSurfaceStub.hpp b/Tests/Surfaces/LineSurfaceStub.hpp
index 476821f1816cec94a3d2fd6caf6f84024def6bb0..fa945c145f42b310154cb87454944079edafe685 100644
--- a/Tests/Surfaces/LineSurfaceStub.hpp
+++ b/Tests/Surfaces/LineSurfaceStub.hpp
@@ -5,9 +5,7 @@
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
-#ifndef ACTS_TESTS_SURFACES_LINESURFACESTUB
-#define ACTS_TESTS_SURFACES_LINESURFACESTUB 1
-
+#pragma once
 //
 #include "Acts/Surfaces/LineSurface.hpp"
 #include "Acts/Utilities/Definitions.hpp"
@@ -76,5 +74,4 @@ public:
     return true;
   }
 };
-}  // end of ns
-#endif
+}  // end of ns
\ No newline at end of file
diff --git a/Tests/Surfaces/SurfaceStub.hpp b/Tests/Surfaces/SurfaceStub.hpp
index 415536b1941f061af49da1c5c0634722c6a9f733..e8331f8175e5a43c5a6a7f7edaa0278abcd68cca 100644
--- a/Tests/Surfaces/SurfaceStub.hpp
+++ b/Tests/Surfaces/SurfaceStub.hpp
@@ -5,9 +5,7 @@
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
-#ifndef ACTS_TEST_SURFACESTUB
-#define ACTS_TEST_SURFACESTUB 1
-
+#pragma once
 #include "Acts/Surfaces/InfiniteBounds.hpp"  //to get s_noBounds
 #include "Acts/Surfaces/PlanarBounds.hpp"
 #include "Acts/Surfaces/Surface.hpp"
@@ -135,5 +133,4 @@ private:
   /// the bounds of this surface
   std::shared_ptr<const PlanarBounds> m_bounds;
 };
-}
-#endif
+}
\ No newline at end of file
diff --git a/doc/Modules.hpp b/doc/Modules.hpp
index c5068e28bf56a2bc8c885add03a96d832e591b77..aa9e976671854f84dc79b6949d61afc09564bb63 100644
--- a/doc/Modules.hpp
+++ b/doc/Modules.hpp
@@ -6,8 +6,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef ACTS_MODULES_HPP
-#define ACTS_MODULES_HPP 1
+#pragma once
 // clang-format off
 
 /// @defgroup Design Design and concept descriptions
@@ -425,5 +424,4 @@
 
 /// @defgroup Contributing Contribution guide
 
-// clang-format on
-#endif  // ACTS_MODULES_HPP
+// clang-format on
\ No newline at end of file