Move <ctime> include out of line

include/internal/catch_tostring.cpp

@@ -216,6 +216,56 @@ std::string StringMaker<double>::convert(double value) {
     return fpToString(value, 10);
 }
 
+// Separate std::chrono::duration specialization
+#if defined(CATCH_CONFIG_ENABLE_CHRONO_STRINGMAKER)
+#include <ctime>
+
+std::string ratio_string<std::atto>::symbol() {
+    return "a";
+}
+
+std::string ratio_string<std::femto>::symbol() {
+    return "f";
+}
+
+std::string ratio_string<std::pico>::symbol() {
+    return "p";
+}
+
+std::string ratio_string<std::nano>::symbol() {
+    return "n";
+}
+
+std::string ratio_string<std::micro>::symbol() {
+    return "u";
+}
+
+std::string ratio_string<std::milli>::symbol() {
+    return "m";
+}
+
+
+std::string time_t_toString(time_t const& toConvert) {
+
+#ifdef _MSC_VER
+    std::tm timeInfo = {};
+    gmtime_s(&timeInfo, &toConvert);
+#else
+    std::tm* timeInfo = std::gmtime(&toConvert);
+#endif
+
+    auto const timeStampSize = sizeof("2017-01-16T17:06:45Z");
+    char timeStamp[timeStampSize];
+    const char * const fmt = "%Y-%m-%dT%H:%M:%SZ";
+
+#ifdef _MSC_VER
+    std::strftime(timeStamp, timeStampSize, fmt, &timeInfo);
+#else
+    std::strftime(timeStamp, timeStampSize, fmt, timeInfo);
+#endif
+    return std::string(timeStamp, timeStampSize);
+}
+#endif // CATCH_CONFIG_ENABLE_CHRONO_STRINGMAKER
 
 } // end namespace Catch