Fix gsl/util for c++20 compilers without <span>

For instance, clang 10 sets __cplusplus >= 202002L yet does not have span, which causes build errors: https://gcc.godbolt.org/z/Yq345zGea
microsoft · Sep 6, 2021 · 83acddc · 83acddc
1 parent 8a4b9ed
commit 83acddc
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/include/gsl/util b/include/gsl/util
@@ -26,7 +26,10 @@
 #include <utility>          // for exchange, forward
 
 #if defined(__cplusplus) && __cplusplus >= 202002L
+#include <version>
+#if defined(__cpp_lib_span) && __cpp_lib_span >= 202002L
 #include <span>
+#endif // __cpp_lib_span >= 202002L
 #endif // __cplusplus >= 202002L
 
 #if defined(_MSC_VER) && !defined(__clang__)