Fixed Autodetect C++14

AlexeyAB · AlexeyAB · commit 4cafca63a270 · 2018-10-03T23:27:11.000+03:00
diff --git a/safe_ptr.h b/safe_ptr.h
@@ -20,7 +20,7 @@
 #include <algorithm>
 
 // Autodetect C++14
-#if _cplusplus >= 201402L
+#if (__cplusplus >= 201402L || _MSC_VER >= 1900)
 #define SHARED_MTX
 #include <shared_mutex>
 #endif
