[bugfix] Make TSC::calibrationIterations a function

dune/perftool/common/tsc.cc

@@ -173,9 +173,9 @@ namespace Dune {
             {
               std::string calibration_method = params->get<std::string>("calibration_method","min");
               if (calibration_method == "min")
-                _overhead = impl::calibrate_tsc_overhead_min(params->get<std::size_t>("calibration_iterations",TSC::calibrationIterations));
+                _overhead = impl::calibrate_tsc_overhead_min(params->get<std::size_t>("calibration_iterations",TSC::calibrationIterations()));
               else if (calibration_method == "median")
-                _overhead = impl::calibrate_tsc_overhead_median(params->get<std::size_t>("calibration_iterations",TSC::calibrationIterations));
+                _overhead = impl::calibrate_tsc_overhead_median(params->get<std::size_t>("calibration_iterations",TSC::calibrationIterations()));
               else
                 DUNE_THROW(TSCError,"Unknown TSC calibration method " << calibration_method);
             }
@@ -185,7 +185,7 @@ namespace Dune {
       else
         {
           _frequency = impl::get_tsc_frequency();
-          _overhead = impl::calibrate_tsc_overhead_min(TSC::calibrationIterations);
+          _overhead = impl::calibrate_tsc_overhead_min(TSC::calibrationIterations());
         }
       _scale_factor = 1.0 / _frequency;
     }

dune/perftool/common/tsc.hh

@@ -18,7 +18,10 @@ namespace Dune {
 
       using Counter = std::uint64_t;
 
-      static constexpr std::size_t calibrationIterations = 100000;
+      static constexpr std::size_t calibrationIterations()
+      {
+        return 100000;
+      }
 
       static Counter start()
       {