Only enable C++17 usings under MSVC if C++17 mode is enabled

Summary: Because not everyone is at C++17 yet.

Reviewed By: yfeldblum

Differential Revision: D7751672

fbshipit-source-id: bcca4d4da67d56be0217a940144977f1cc98e5a1

folly/Portability.h

@@ -410,7 +410,8 @@ constexpr auto kCpplibVer = 0;
 #define FOLLY_HAS_COROUTINES 1
 #endif
 
-// MSVC 2017.5
-#if __cpp_noexcept_function_type >= 201510 || _MSC_FULL_VER >= 191225816
+// MSVC 2017.5 && C++17
+#if __cpp_noexcept_function_type >= 201510 || \
+    (_MSC_FULL_VER >= 191225816 && _MSVC_LANG > 201402)
 #define FOLLY_HAVE_NOEXCEPT_FUNCTION_TYPE 1
 #endif

folly/functional/ApplyTuple.h

@@ -152,7 +152,7 @@ auto uncurry(F&& f)
       std::forward<F>(f));
 }
 
-#if __cpp_lib_make_from_tuple || _MSC_VER >= 1910
+#if __cpp_lib_make_from_tuple || (_MSC_VER >= 1910 && _MSVC_LANG > 201402)
 
 /* using override */ using std::make_from_tuple;
 

folly/functional/Invoke.h

@@ -61,8 +61,9 @@ constexpr auto invoke(M(C::*d), Args&&... args)
 
 #endif
 
-// Only available in >= MSVC 2017 15.3
-#if __cpp_lib_is_invocable >= 201703 || _MSC_VER >= 1911
+// Only available in >= MSVC 2017 15.3 in C++17
+#if __cpp_lib_is_invocable >= 201703 || \
+    (_MSC_VER >= 1911 && _MSVC_LANG > 201402)
 
 namespace folly {