Implement is_error_code_v and is_error_condition_v for c++17. Rework the tests for is_error_code and is_error_condition, since they were really lacking. Thanks to Alisdair for the heads-up that we were missing these.

llvm-svn: 282331

1 files changed, 16 insertions, 0 deletions

diff --git a/libcxx/include/system_error b/libcxx/include/system_error
index 5145d23e630..faaeaa06d05 100644
--- a/libcxx/include/system_error
+++ b/libcxx/include/system_error
@@ -46,6 +46,12 @@ template <class T> struct is_error_code_enum
 template <class T> struct is_error_condition_enum
     : public false_type {};
 
+template <class _Tp>
+constexpr size_t is_error_condition_enum_v = is_error_condition_enum<_Tp>::value; // C++17
+
+template <class _Tp>
+constexpr size_t is_error_code_enum_v = is_error_code_enum<_Tp>::value; // C++17
+
 class error_code
 {
 public:
@@ -236,12 +242,22 @@ template <class _Tp>
 struct _LIBCPP_TYPE_VIS_ONLY is_error_code_enum
     : public false_type {};
 
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+constexpr size_t is_error_code_enum_v = is_error_code_enum<_Tp>::value;
+#endif
+
 // is_error_condition_enum
 
 template <class _Tp>
 struct _LIBCPP_TYPE_VIS_ONLY is_error_condition_enum
     : public false_type {};
 
+#if _LIBCPP_STD_VER > 14
+template <class _Tp>
+constexpr size_t is_error_condition_enum_v = is_error_condition_enum<_Tp>::value;
+#endif
+
 // Some error codes are not present on all platforms, so we provide equivalents
 // for them: