nxcomp/{configure.ac,Log.cpp}: implement configure-time std::put_time check and…

nxcomp/configure.ac

@@ -74,6 +74,23 @@ AC_ARG_ENABLE([cxx11],
               [AS_IF([test x$enableval = xyes],
                     [AX_CXX_COMPILE_STDCXX_11([], [mandatory])])])
 
+# Check if std::put_time is available.
+AC_MSG_CHECKING([if std::put_time is available])
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
+[[
+#include <iomanip>
+#include <ctime>
+]],
+[[
+std::time_t t = std::time(NULL);
+std::tm tm = *std::localtime(&t);
+(void) std::put_time(&tm, "%c");
+]])],
+                  [AC_MSG_RESULT([yes])
+                   AC_DEFINE(HAVE_STD_PUT_TIME, [1],
+                             [Use std::put_time to format times, must be made available by the compiler if turned on.])],
+                  [AC_MSG_RESULT([no])])
+
 AC_ARG_ENABLE([debug],
               [AS_HELP_STRING([--enable-debug],
                               [enable to get info session log output (disabled by default)])],

nxcomp/src/Log.cpp

@@ -31,6 +31,7 @@
 #include <iomanip>
 
 #include "Log.h"
+#include "config.h"
 
 NXLog nx_log;
 
@@ -78,7 +79,7 @@ std::string NXLog::stamp_to_string(const NXLogStamp& stamp) const
         }
         else
         {
-            #if __cplusplus >= 201103L && (!defined(__GNUC__) || __GNUC__ >= 5)
+            #if HAVE_STD_PUT_TIME
             oss << " " << std::put_time(&timeinfo, "%Y/%m/%d %H:%M:%S");
             #else
             oss << timestamp.tv_sec;