[libc++] Move __core_convertible_to into __type_traits/is_core_convertible.h

Signed-off-by: yronglin <[email protected]>

Author: yronglin

libcxx/include/CMakeLists.txt

@@ -307,7 +307,6 @@ set(files
   __concepts/constructible.h
   __concepts/convertible_to.h
   __concepts/copyable.h
-  __concepts/core_convertible_to.h
   __concepts/derived_from.h
   __concepts/destructible.h
   __concepts/different_from.h

libcxx/include/__concepts/core_convertible_to.h

@@ -10,7 +10,6 @@
 #define _LIBCPP___EXPECTED_EXPECTED_H
 
 #include <__assert>
-#include <__concepts/core_convertible_to.h>
 #include <__config>
 #include <__expected/bad_expected_access.h>
 #include <__expected/unexpect.h>
@@ -26,6 +25,7 @@
 #include <__type_traits/is_assignable.h>
 #include <__type_traits/is_constructible.h>
 #include <__type_traits/is_convertible.h>
+#include <__type_traits/is_core_convertible.h>
 #include <__type_traits/is_function.h>
 #include <__type_traits/is_nothrow_assignable.h>
 #include <__type_traits/is_nothrow_constructible.h>

libcxx/include/__expected/expected.h

@@ -30,6 +30,14 @@ template <class _Tp, class _Up>
 struct __is_core_convertible<_Tp, _Up, decltype(static_cast<void (*)(_Up)>(0)(static_cast<_Tp (*)()>(0)()))>
     : true_type {};
 
+
+#if _LIBCPP_STD_VER >= 20
+
+template <class _Tp, class _Up>
+concept __core_convertible_to = __is_core_convertible_v<_Tp, _Up>;
+
+#endif // _LIBCPP_STD_VER >= 20
+
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___TYPE_TRAITS_IS_CORE_CONVERTIBLE_H

libcxx/include/__type_traits/is_core_convertible.h

@@ -1075,7 +1075,6 @@ module std [system] {
     module constructible            { header "__concepts/constructible.h" }
     module convertible_to           { header "__concepts/convertible_to.h" }
     module copyable                 { header "__concepts/copyable.h" }
-    module core_convertible_to      { header "__concepts/core_convertible_to.h" }
     module derived_from             { header "__concepts/derived_from.h" }
     module destructible             { header "__concepts/destructible.h" }
     module different_from           { header "__concepts/different_from.h" }