Fix static assert warning in TimingServiceBase

Moved a static member data to be a static const function variable.

Author: Dr15Jones

FWCore/AbstractServices/interface/TimingServiceBase.h

@@ -42,10 +42,7 @@ namespace edm {
 
     static void jobStarted();
 
-    static std::chrono::steady_clock::time_point jobStartTime() { return s_jobStartTime; }
-
-  private:
-    static std::chrono::steady_clock::time_point s_jobStartTime;
+    static std::chrono::steady_clock::time_point jobStartTime();
   };
 }  // namespace edm
 

FWCore/AbstractServices/src/TimingServiceBase.cc

@@ -14,12 +14,14 @@
 
 using namespace edm;
 
-std::chrono::steady_clock::time_point TimingServiceBase::s_jobStartTime;
-
 void TimingServiceBase::jobStarted() {
-  if (0 == s_jobStartTime.time_since_epoch().count()) {
-    s_jobStartTime = std::chrono::steady_clock::now();
-  }
+  //make sure the value has been initialized
+  (void)jobStartTime();
+}
+
+std::chrono::steady_clock::time_point TimingServiceBase::jobStartTime() {
+  static const std::chrono::steady_clock::time_point s_jobStartTime = std::chrono::steady_clock::now();
+  return s_jobStartTime;
 }
 
 //