suppress "integral constant overflow" warning under msvc 2017

src/bundled_fmtlib_format.cpp

@@ -7,8 +7,19 @@
 #endif
 
 #if !defined(SPDLOG_FMT_EXTERNAL) && !defined(SPDLOG_USE_STD_FORMAT)
+
+// suppress "integral constant overflow" warning under msvc 2017 (which doesn't appear in other msvc versions)
+#if defined(_MSC_VER) && (_MSC_VER >= 1910) && (_MSC_VER <= 1916)
+#    pragma warning(push)
+#    pragma warning(disable : 4307)
+#endif
 #    include <spdlog/fmt/bundled/format-inl.h>
 
+#if defined(_MSC_VER)
+#    pragma warning(pop)
+#endif
+
+
 FMT_BEGIN_NAMESPACE
 namespace detail {