commit 7e99e76c9761d0d0b0848b91f8648830670ee872
author Jordan Maples [MSFT] <49793787+JordanMaples@users.noreply.github.com> Mon Nov 18 13:02:53 2019 -0800
committer GitHub <noreply@github.com> Mon Nov 18 13:02:53 2019 -0800
tree e9b1ccab3d8615a381d6895afff8cfff7536f400
parent 9939d5889bc2bcde2ac17a026313d0960d6d799a
parent 263440f2a10cf016b0ab18071508b6fde4ebdfc6

Merge pull request #826 from JordanMaples/dev/jomaples/ctad_fix_v2

fix ctad warning in llvm

include/gsl/gsl_byte

diff --git a/include/gsl/gsl_byte b/include/gsl/gsl_byte
index 1670646..c2fc572 100644
--- a/include/gsl/gsl_byte
+++ b/include/gsl/gsl_byte
@@ -33,6 +33,8 @@
 
 #include <type_traits>
 
+// VS2017 15.8 added support for the __cpp_lib_byte definition
+// To do: drop _HAS_STD_BYTE when support for pre 15.8 expires
 #ifdef _MSC_VER
 
 #pragma warning(push)
@@ -42,15 +44,15 @@
 
 #ifndef GSL_USE_STD_BYTE
 // this tests if we are under MSVC and the standard lib has std::byte and it is enabled
-#if defined(_HAS_STD_BYTE) && _HAS_STD_BYTE
+#if (defined(_HAS_STD_BYTE) && _HAS_STD_BYTE) || (defined(__cpp_lib_byte) && __cpp_lib_byte >= 201603)
 
 #define GSL_USE_STD_BYTE 1
 
-#else // defined(_HAS_STD_BYTE) && _HAS_STD_BYTE
+#else // (defined(_HAS_STD_BYTE) && _HAS_STD_BYTE) || (defined(__cpp_lib_byte) && __cpp_lib_byte >= 201603)
 
 #define GSL_USE_STD_BYTE 0
 
-#endif // defined(_HAS_STD_BYTE) && _HAS_STD_BYTE
+#endif // (defined(_HAS_STD_BYTE) && _HAS_STD_BYTE) || (defined(__cpp_lib_byte) && __cpp_lib_byte >= 201603)
 #endif // GSL_USE_STD_BYTE
 
 #else // _MSC_VER