partially fix msvc build

fpm/src/fTimers.cpp

@@ -87,7 +87,7 @@ void Timers::write(std::ostream &out) const
         << std::setw(15) << std::right << "CPU (s)"
         << std::endl;
 
-    for (auto const tm : timers)
+    for (auto const &tm : timers)
     {
         out << std::setw(20) << std::left << tm.first
             << std::setw(15) << std::right << tm.second.getWall()

fpm/src/fTimers.h

@@ -21,6 +21,8 @@
 #include "wObject.h"
 #include <map>
 #include <chrono>
+#include <ctime>
+#include <string>
 
 namespace fpm
 {