Re: [PATCH] Add C++20 Traits for [Un]bounded Arrays (P1357R1)

[Jonathan Wakely]

On 06/03/19 12:13 +0000, Jonathan Wakely wrote:

         * include/std/type_traits [C++20] (is_bounded_array)
         (is_unbounded_array, is_bounded_array_v, is_unbounded_array_v):
         Define.
         * testsuite/20_util/is_bounded_array/requirements/
         explicit_instantiation.cc: New test.
         * testsuite/20_util/is_bounded_array/requirements/typedefs.cc: New
         test.
         * testsuite/20_util/is_bounded_array/value.cc: New test.
         * testsuite/20_util/is_unbounded_array/requirements/
         explicit_instantiation.cc: New test.
         * testsuite/20_util/is_unbounded_array/requirements/typedefs.cc: New
         * test.
         * testsuite/20_util/is_unbounded_array/value.cc: New test.

I forgot the feature test macro. I'll commit this after testing ...


commit 1d2785fd303eaf89daea9aff31d6164e75ff7e22
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Wed Mar 6 12:28:00 2019 +0000

    Add feature test macro for bounded array traits
    
            * include/std/type_traits (__cpp_lib_bounded_array_traits): Define.
            * include/std/version (__cpp_lib_bounded_array_traits): Likewise.
            * testsuite/20_util/is_bounded_array/value.cc: Check for macro.
            * testsuite/20_util/is_unbounded_array/value.cc: Likewise.

diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits
index a1161d50399..c3cb67a457d 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -3074,6 +3074,8 @@ template <typename _From, typename _To>
   template<typename _Tp>
     using unwrap_ref_decay_t = typename unwrap_ref_decay<_Tp>::type;
 
+#define __cpp_lib_bounded_array_traits 201902L
+
   /// True for a type that is an array of known bound.
   template<typename _Tp>
     struct is_bounded_array
diff --git a/libstdc++-v3/include/std/version b/libstdc++-v3/include/std/version
index 785e8966dbf..668b477e24d 100644
--- a/libstdc++-v3/include/std/version
+++ b/libstdc++-v3/include/std/version
@@ -148,6 +148,7 @@
 
 #if __cplusplus > 201703L
 // c++2a
+#define __cpp_lib_bounded_array_traits 201902L
 #if __cpp_impl_destroying_delete
 # define __cpp_lib_destroying_delete 201806L
 #endif
diff --git a/libstdc++-v3/testsuite/20_util/is_bounded_array/value.cc b/libstdc++-v3/testsuite/20_util/is_bounded_array/value.cc
index 9f37d36e532..47ecae8ca05 100644
--- a/libstdc++-v3/testsuite/20_util/is_bounded_array/value.cc
+++ b/libstdc++-v3/testsuite/20_util/is_bounded_array/value.cc
@@ -21,6 +21,12 @@
 #include <type_traits>
 #include <testsuite_tr1.h>
 
+#ifndef __cpp_lib_bounded_array_traits
+# error "Feature test macro for is_bounded_array is missing"
+#elif __cpp_lib_bounded_array_traits < 201902L
+# error "Feature test macro for is_bounded_array has wrong value"
+#endif
+
 void test01()
 {
   using std::is_bounded_array;
diff --git a/libstdc++-v3/testsuite/20_util/is_unbounded_array/value.cc b/libstdc++-v3/testsuite/20_util/is_unbounded_array/value.cc
index 28a77b21da2..19fb0524cd8 100644
--- a/libstdc++-v3/testsuite/20_util/is_unbounded_array/value.cc
+++ b/libstdc++-v3/testsuite/20_util/is_unbounded_array/value.cc
@@ -21,6 +21,12 @@
 #include <type_traits>
 #include <testsuite_tr1.h>
 
+#ifndef __cpp_lib_bounded_array_traits
+# error "Feature test macro for is_unbounded_array is missing"
+#elif __cpp_lib_bounded_array_traits < 201902L
+# error "Feature test macro for is_unbounded_array has wrong value"
+#endif
+
 void test01()
 {
   using std::is_unbounded_array;