Avoid undefined symbols with mingw-w64 (#2692)

rbberger · web-flow · commit fc1783fcc603 · 2022-01-03T15:29:29.000-08:00
Fixes issue #2691
diff --git a/include/fmt/chrono.h b/include/fmt/chrono.h
@@ -1082,7 +1082,7 @@ template <typename OutputIt, typename Char> class tm_writer {
   }
   template <typename T, FMT_ENABLE_IF(!has_member_data_tm_gmtoff<T>::value)>
   void format_utc_offset_impl(const T& tm) {
-#if defined(_WIN32)
+#if defined(_WIN32) && defined(_UCRT)
 #  if FMT_USE_TZSET
     tzset_once();
 #  endif

Original file line number	Diff line number	Diff line change
`@@ -1082,7 +1082,7 @@ template <typename OutputIt, typename Char> class tm_writer {`
`1082`	`1082`	`}`
`1083`	`1083`	`template <typename T, FMT_ENABLE_IF(!has_member_data_tm_gmtoff<T>::value)>`
`1084`	`1084`	`void format_utc_offset_impl(const T& tm) {`
`1085`		`-#if defined(_WIN32)`
	`1085`	`+#if defined(_WIN32) && defined(_UCRT)`
`1086`	`1086`	`# if FMT_USE_TZSET`
`1087`	`1087`	`tzset_once();`
`1088`	`1088`	`# endif`