From 166ea80f669da8ce1019a814a966b76024ee2c16 Mon Sep 17 00:00:00 2001
From: Casey Carter <Casey@Carter.net>
Date: Wed, 18 Oct 2017 16:35:11 -0700
Subject: [PATCH] Update std::byte detection in gsl_byte for MSVC (#561)

* Only check that `_HAS_STD_BYTE` is defined to a non-zero value
---
 include/gsl/gsl_byte | 6 +++---
 tests/unittest-cpp   | 1 +
 2 files changed, 4 insertions(+), 3 deletions(-)
 create mode 160000 tests/unittest-cpp

diff --git a/include/gsl/gsl_byte b/include/gsl/gsl_byte
index 1e2e3be..7155210 100644
--- a/include/gsl/gsl_byte
+++ b/include/gsl/gsl_byte
@@ -30,15 +30,15 @@
 
 #ifndef GSL_USE_STD_BYTE
 // this tests if we are under MSVC and the standard lib has std::byte and it is enabled
-#if _MSC_VER >= 1911 && (!defined(_HAS_STD_BYTE) || _HAS_STD_BYTE)
+#if defined(_HAS_STD_BYTE) && _HAS_STD_BYTE
 
 #define GSL_USE_STD_BYTE 1
 
-#else // _MSC_VER >= 1911 && (!defined(_HAS_STD_BYTE) || _HAS_STD_BYTE)
+#else // defined(_HAS_STD_BYTE) && _HAS_STD_BYTE
 
 #define GSL_USE_STD_BYTE 0
 
-#endif // _MSC_VER >= 1911 && (!defined(_HAS_STD_BYTE) || _HAS_STD_BYTE)
+#endif // defined(_HAS_STD_BYTE) && _HAS_STD_BYTE
 #endif // GSL_USE_STD_BYTE
 
 #else // _MSC_VER
diff --git a/tests/unittest-cpp b/tests/unittest-cpp
new file mode 160000
index 0000000..dc6b908
--- /dev/null
+++ b/tests/unittest-cpp
@@ -0,0 +1 @@
+Subproject commit dc6b90838014ab985bf3cd74ac17ad9d00e1fbcb