diff --git a/GaudiKernel/GaudiKernel/EventIDBase.h b/GaudiKernel/GaudiKernel/EventIDBase.h
index c79166cac54531dcca745c559e2e8ee79d2eef18..e8c43ed107ec25c40a55d97a49a5c2c161592ade 100644
--- a/GaudiKernel/GaudiKernel/EventIDBase.h
+++ b/GaudiKernel/GaudiKernel/EventIDBase.h
@@ -74,7 +74,7 @@ public:
                number_type time_stamp_ns_offset = 0, number_type lumi_block = UNDEFNUM,
                number_type bunch_crossing_id = 0 );
   // Use default copy constructor.
-  virtual ~EventIDBase();
+  virtual ~EventIDBase() = default;
   //@}
 
   /// run number - 32 bit unsigned
@@ -133,18 +133,18 @@ public:
   void set_bunch_crossing_id( number_type bcid ) { m_bunch_crossing_id = bcid; }
 
   /// Comparison operators
-  friend bool operator<( const EventIDBase& lhs, const EventIDBase& rhs );
-  friend bool operator>( const EventIDBase& lhs, const EventIDBase& rhs );
   friend bool operator==( const EventIDBase& lhs, const EventIDBase& rhs );
-  friend bool operator!=( const EventIDBase& lhs, const EventIDBase& rhs );
-  friend bool operator<=( const EventIDBase& lhs, const EventIDBase& rhs );
-  friend bool operator>=( const EventIDBase& lhs, const EventIDBase& rhs );
+  friend bool operator<( const EventIDBase& lhs, const EventIDBase& rhs );
+  friend bool operator>( const EventIDBase& lhs, const EventIDBase& rhs ) { return rhs < lhs; }
+  friend bool operator!=( const EventIDBase& lhs, const EventIDBase& rhs ) { return !( lhs == rhs ); }
+  friend bool operator<=( const EventIDBase& lhs, const EventIDBase& rhs ) { return !( lhs > rhs ); }
+  friend bool operator>=( const EventIDBase& lhs, const EventIDBase& rhs ) { return !( lhs < rhs ); }
 
-  bool isRunEvent() const;
-  bool isTimeStamp() const;
-  bool isLumiEvent() const;
-  bool isRunLumi() const;
-  bool isValid() const;
+  bool isRunEvent() const { return m_type & RunEvent; }
+  bool isTimeStamp() const { return m_type & TimeStamp; }
+  bool isLumiEvent() const { return m_type & LumiEvent; }
+  bool isRunLumi() const { return m_type & RunLumi; }
+  bool isValid() const { return m_type != Invalid; }
 
   /// Extraction operators
   friend std::ostream& operator<<( std::ostream& os, const EventIDBase& rhs );
@@ -178,10 +178,10 @@ private:
 
   unsigned m_type{Invalid};
 
-  void setRE() { m_type = m_type | RunEvent; }
-  void setTS() { m_type = m_type | TimeStamp; }
-  void setLE() { m_type = m_type | LumiEvent; }
-  void setRL() { m_type = m_type | RunLumi; }
+  void setRE() { m_type |= RunEvent; }
+  void setTS() { m_type |= TimeStamp; }
+  void setLE() { m_type |= LumiEvent; }
+  void setRL() { m_type |= RunLumi; }
 
   /// run number
   number_type m_run_number{UNDEFNUM};
@@ -223,10 +223,6 @@ inline bool operator==( const EventIDBase& lhs, const EventIDBase& rhs )
   return ( lhs.m_run_number == rhs.m_run_number && lhs.m_event_number == rhs.m_event_number &&
            lhs.m_lumi_block == rhs.m_lumi_block );
 }
-inline bool operator>( const EventIDBase& lhs, const EventIDBase& rhs ) { return rhs < lhs; }
-inline bool operator!=( const EventIDBase& lhs, const EventIDBase& rhs ) { return !( lhs == rhs ); }
-inline bool operator<=( const EventIDBase& lhs, const EventIDBase& rhs ) { return !( lhs > rhs ); }
-inline bool operator>=( const EventIDBase& lhs, const EventIDBase& rhs ) { return !( lhs < rhs ); }
 
 inline std::ostream& operator<<( std::ostream& os, const EventIDBase& rhs )
 {
diff --git a/GaudiKernel/src/Lib/EventIDBase.cpp b/GaudiKernel/src/Lib/EventIDBase.cpp
index 7ced0b3369b9716bcf454be12a0443f08bc4fa90..184df9abec854d6e1c3c956e183c42e8e5ef2438 100644
--- a/GaudiKernel/src/Lib/EventIDBase.cpp
+++ b/GaudiKernel/src/Lib/EventIDBase.cpp
@@ -23,34 +23,14 @@ EventIDBase::EventIDBase( number_type run_number, event_number_t event_number, n
     , m_lumi_block( lumi_block )
     , m_bunch_crossing_id( bunch_crossing_id )
 {
-  if ( m_run_number != UNDEFNUM && m_event_number != UNDEFEVT ) {
-    setRE();
-  }
+  if ( m_run_number != UNDEFNUM && m_event_number != UNDEFEVT ) setRE();
 
   if ( m_time_stamp != UNDEFNUM ) {
     setTS();
-    if ( m_time_stamp_ns_offset == UNDEFNUM ) {
-      m_time_stamp_ns_offset = 0;
-    }
+    if ( m_time_stamp_ns_offset == UNDEFNUM ) m_time_stamp_ns_offset = 0;
   }
 
-  if ( m_lumi_block != UNDEFNUM && m_event_number != UNDEFEVT ) {
-    setLE();
-  }
+  if ( m_lumi_block != UNDEFNUM && m_event_number != UNDEFEVT ) setLE();
 
-  if ( m_run_number != UNDEFNUM && m_lumi_block != UNDEFNUM ) {
-    setRL();
-  }
+  if ( m_run_number != UNDEFNUM && m_lumi_block != UNDEFNUM ) setRL();
 }
-
-EventIDBase::~EventIDBase() {}
-
-bool EventIDBase::isRunEvent() const { return ( m_type & RunEvent ); }
-
-bool EventIDBase::isTimeStamp() const { return ( m_type & TimeStamp ); }
-
-bool EventIDBase::isLumiEvent() const { return ( m_type & LumiEvent ); }
-
-bool EventIDBase::isRunLumi() const { return ( m_type & RunLumi ); }
-
-bool EventIDBase::isValid() const { return ( m_type != Invalid ); }