Add std::__is_byte<std::byte> specialization

	* include/bits/cpp_type_traits.h [__cplusplus >= 201703]
	(__is_byte<byte>): Define specialization for std::byte.

From-SVN: r262182

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 0db12be..97a8076 100644 (file)
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,8 @@
 2018-06-27  Jonathan Wakely  <jwakely@redhat.com>
 
+       * include/bits/cpp_type_traits.h [__cplusplus >= 201703]
+       (__is_byte<byte>): Define specialization for std::byte.
+
        PR libstdc++/86138
        * include/bits/basic_string.tcc: [_GLIBCXX_EXTERN_TEMPLATE < 0]
        Declare explicit instantiations of COW empty reps and I/O functions.

diff --git a/libstdc++-v3/include/bits/cpp_type_traits.h b/libstdc++-v3/include/bits/cpp_type_traits.h
index ed6de46..960d469 100644 (file)
--- a/libstdc++-v3/include/bits/cpp_type_traits.h
+++ b/libstdc++-v3/include/bits/cpp_type_traits.h
@@ -391,6 +391,17 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3)
       typedef __true_type __type;
     };
 
+#if __cplusplus >= 201703L
+  enum class byte : unsigned char;
+
+  template<>
+    struct __is_byte<byte>
+    {
+      enum { __value = 1 };
+      typedef __true_type __type;
+    };
+#endif // C++17
+
   //
   // Move iterator type
   //