diff --git a/Tracking/TrkDetDescr/TrkSurfaces/TrkSurfaces/DistanceSolution.h b/Tracking/TrkDetDescr/TrkSurfaces/TrkSurfaces/DistanceSolution.h
index 60ee6ea87fed1f56e8807a616da6585214a3295f..d38c5f9e771410f817509915881c672c1128aeab 100644
--- a/Tracking/TrkDetDescr/TrkSurfaces/TrkSurfaces/DistanceSolution.h
+++ b/Tracking/TrkDetDescr/TrkSurfaces/TrkSurfaces/DistanceSolution.h
@@ -9,9 +9,7 @@
 #ifndef TRKSURFACES_DISTANCESOLUTION_H
 #define TRKSURFACES_DISTANCESOLUTION_H
 
-// STD
-#include <iostream>
-#include <math.h>
+#include <cmath>
 
 namespace Trk {
 
@@ -26,14 +24,19 @@ namespace Trk {
 class DistanceSolution
 {
 public:
-  /**Default Constructor*/
-  DistanceSolution();
-
-  /**Constructor*/
-  DistanceSolution(int num, double current = 0., bool signedDist = false, double first = 0., double second = 0.);
-
-  /**Destructor*/
-  virtual ~DistanceSolution() = default;
+  DistanceSolution() = default;
+  DistanceSolution(const DistanceSolution&) = default;
+  DistanceSolution(DistanceSolution&&) = default;
+  DistanceSolution& operator=(const DistanceSolution&) = default;
+  DistanceSolution& operator=(DistanceSolution&&) = default;
+  ~DistanceSolution() = default;
+
+   /**Constructor*/
+  DistanceSolution(int num,
+                   double current = 0.,
+                   bool signedDist = false,
+                   double first = 0.,
+                   double second = 0.);
 
   // methods to access solutions
   /** Number of intersection solutions*/
@@ -42,7 +45,8 @@ public:
   /** Distance to first intersection solution along direction*/
   double first() const;
 
-  /** Distance to second intersection solution along direction (for a cylinder surface)*/
+  /** Distance to second intersection solution along direction (for a cylinder
+   * surface)*/
   double second() const;
 
   /** Absolute Distance to closest solution */
@@ -51,14 +55,15 @@ public:
   /** Distance to point of closest approach along direction*/
   double toPointOfClosestApproach() const;
 
-  /** Current distance to surface (spatial), signed (along/opposite to surface normal) if input argument true (absolute
-   * value by default)*/
+  /** Current distance to surface (spatial), signed (along/opposite to surface
+   * normal) if input argument true (absolute value by default)*/
   double currentDistance(bool signedDist = false) const;
 
-  /** This method indicates availability of signed current distance (false for Perigee and StraighLineSurface) */
+  /** This method indicates availability of signed current distance (false for
+   * Perigee and StraighLineSurface) */
   bool signedDistance() const;
 
-protected:
+private:
   int m_num;
   double m_first;
   double m_second;
@@ -66,54 +71,7 @@ protected:
   bool m_signedDist;
 };
 
-inline int
-DistanceSolution::numberOfSolutions() const
-{
-  return m_num;
-}
-
-inline double
-DistanceSolution::first() const
-{
-  return m_first;
-}
-
-inline double
-DistanceSolution::second() const
-{
-  return m_second;
-}
-
-inline double
-DistanceSolution::absClosest() const
-{
-  if (m_num > 1)
-    return (m_first * m_first < m_second * m_second) ? fabs(m_first) : fabs(m_second);
-  else
-    return fabs(m_first);
-}
-
-inline double
-DistanceSolution::toPointOfClosestApproach() const
-{
-  return m_first;
-}
-
-inline double
-DistanceSolution::currentDistance(bool signedDist) const
-{
-  if (signedDist)
-    return m_current;
-  else
-    return fabs(m_current);
-}
-
-inline bool
-DistanceSolution::signedDistance() const
-{
-  return m_signedDist;
-}
-
 } // end of namespace
 
+#include "TrkSurfaces/DistanceSolution.icc"
 #endif // TRKSURFACES_DISTANCESOLUTION_H
diff --git a/Tracking/TrkDetDescr/TrkSurfaces/TrkSurfaces/DistanceSolution.icc b/Tracking/TrkDetDescr/TrkSurfaces/TrkSurfaces/DistanceSolution.icc
new file mode 100644
index 0000000000000000000000000000000000000000..15ef7e32d23aef44aad1bbcc8319eae1f3bb6b93
--- /dev/null
+++ b/Tracking/TrkDetDescr/TrkSurfaces/TrkSurfaces/DistanceSolution.icc
@@ -0,0 +1,69 @@
+/*
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
+*/
+namespace Trk {
+inline DistanceSolution::DistanceSolution(int num,
+                                          double current,
+                                          bool signedDist,
+                                          double first,
+                                          double second)
+  : m_num(num)
+  , m_first(first)
+  , m_second(second)
+  , m_current(current)
+  , m_signedDist(signedDist)
+{}
+
+inline int
+DistanceSolution::numberOfSolutions() const
+{
+  return m_num;
+}
+
+inline double
+DistanceSolution::first() const
+{
+  return m_first;
+}
+
+inline double
+DistanceSolution::second() const
+{
+  return m_second;
+}
+
+inline double
+DistanceSolution::absClosest() const
+{
+  if (m_num > 1) {
+    return (m_first * m_first < m_second * m_second) ? std::abs(m_first)
+                                                     : std::abs(m_second);
+  } else {
+    return std::abs(m_first);
+  }
+}
+
+inline double
+DistanceSolution::toPointOfClosestApproach() const
+{
+  return m_first;
+}
+
+inline double
+DistanceSolution::currentDistance(bool signedDist) const
+{
+  if (signedDist) {
+    return m_current;
+  } else {
+    return std::abs(m_current);
+  }
+}
+
+inline bool
+DistanceSolution::signedDistance() const
+{
+  return m_signedDist;
+}
+
+} // end of namespace
+
diff --git a/Tracking/TrkDetDescr/TrkSurfaces/src/DistanceSolution.cxx b/Tracking/TrkDetDescr/TrkSurfaces/src/DistanceSolution.cxx
deleted file mode 100644
index a7d7a4cdf54896944a2b300672f0aa0f5635abf6..0000000000000000000000000000000000000000
--- a/Tracking/TrkDetDescr/TrkSurfaces/src/DistanceSolution.cxx
+++ /dev/null
@@ -1,28 +0,0 @@
-/*
-  Copyright (C) 2002-2018 CERN for the benefit of the ATLAS collaboration
-*/
-
-///////////////////////////////////////////////////////////////////
-// DistanceSolution.cxx, (c) ATLAS Detector Software
-///////////////////////////////////////////////////////////////////
-
-// Trk
-#include "TrkSurfaces/DistanceSolution.h"
-
-// default constructor
-Trk::DistanceSolution::DistanceSolution()
-  : m_num()
-  , m_first()
-  , m_second()
-  , m_current()
-  , m_signedDist()
-{}
-
-// constructor
-Trk::DistanceSolution::DistanceSolution(int num, double current, bool signedDist, double first, double second)
-  : m_num(num)
-  , m_first(first)
-  , m_second(second)
-  , m_current(current)
-  , m_signedDist(signedDist)
-{}