From 01eaf5bef131ff51274ca57f5ade2d10851aa00b Mon Sep 17 00:00:00 2001
From: Jordan Maples <jomaples@microsoft.com>
Date: Mon, 10 Aug 2020 16:45:47 -0700
Subject: [PATCH 1/2] macro version

---
 include/gsl/gsl_util | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/include/gsl/gsl_util b/include/gsl/gsl_util
index 89fb2ee..2e79605 100644
--- a/include/gsl/gsl_util
+++ b/include/gsl/gsl_util
@@ -32,6 +32,12 @@
 
 #endif            // _MSC_VER
 
+#if __has_cpp_attribute(nodiscard) >= 201603L
+#define GSL_NODISCARD [[nodiscard]]
+#else
+#define GSL_NODISCARD
+#endif
+
 namespace gsl
 {
 //
@@ -67,13 +73,13 @@ private:
 
 // finally() - convenience function to generate a final_action
 template <class F>
-final_action<F> finally(const F& f) noexcept
+GSL_NODISCARD final_action<F> finally(const F& f) noexcept
 {
     return final_action<F>(f);
 }
 
 template <class F>
-final_action<F> finally(F&& f) noexcept
+GSL_NODISCARD final_action<F> finally(F&& f) noexcept
 {
     return final_action<F>(std::forward<F>(f));
 }
@@ -98,16 +104,16 @@ constexpr
 T narrow(U u) noexcept(false)
 {
     constexpr const bool is_different_signedness = (std::is_signed<T>::value != std::is_signed<U>::value);
-    
+
     const T t = narrow_cast<T>(u);
-    
+
     if (static_cast<U>(t) != u
         || (is_different_signedness
             && ((t < T{}) != (u < U{}))))
     {
         throw narrowing_error{};
     }
-    
+
     return t;
 }
 

From afe824490ebae9188be0e96ecff3dbc73b37285c Mon Sep 17 00:00:00 2001
From: Jordan Maples <jomaples@microsoft.com>
Date: Wed, 12 Aug 2020 12:13:19 -0700
Subject: [PATCH 2/2] change macro test to use __cplusplus instead of
 __has_cpp_attribute

---
 include/gsl/gsl_util | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/gsl/gsl_util b/include/gsl/gsl_util
index 2e79605..974655b 100644
--- a/include/gsl/gsl_util
+++ b/include/gsl/gsl_util
@@ -32,11 +32,11 @@
 
 #endif            // _MSC_VER
 
-#if __has_cpp_attribute(nodiscard) >= 201603L
+#if defined(__cplusplus) && (__cplusplus >= 201703L)
 #define GSL_NODISCARD [[nodiscard]]
 #else
 #define GSL_NODISCARD
-#endif
+#endif // defined(__cplusplus) && (__cplusplus >= 201703L)
 
 namespace gsl
 {