Test for std::format using __cpp_lib_format

Fixes compilation on libc++ 16

Author: mochaaP

include/proxy/v4/proxy.h

@@ -20,9 +20,10 @@
 
 #if __STDC_HOSTED__
 #include <atomic>
-#if __has_include(<format>)
+#include <version>
+#if __cpp_lib_format
 #include <format>
-#endif // __has_include(<format>)
+#endif // __cpp_lib_format
 #endif // __STDC_HOSTED__
 
 #if __cpp_rtti >= 199711L
@@ -2125,7 +2126,7 @@ struct weak_conversion_dispatch : cast_dispatch_base<false, true> {
 template <class F>
 using weak_conversion_overload = weak_proxy<F>() const noexcept;
 
-#if __STDC_HOSTED__ && __has_include(<format>)
+#if __STDC_HOSTED__ && __cpp_lib_format
 template <class CharT>
 struct format_overload_traits;
 template <>
@@ -2166,7 +2167,7 @@ struct format_dispatch {
     return impl.format(self, fc);
   }
 };
-#endif // __STDC_HOSTED__ && __has_include(<format>)
+#endif // __STDC_HOSTED__ && __cpp_lib_format
 
 #if __cpp_rtti >= 199711L
 struct proxy_cast_context {
@@ -2273,7 +2274,7 @@ struct proxy_typeid_reflector {
 
 namespace skills {
 
-#if __STDC_HOSTED__ && __has_include(<format>)
+#if __STDC_HOSTED__ && __cpp_lib_format
 template <class FB>
 using format =
     typename FB::template add_convention<details::format_dispatch,
@@ -2283,7 +2284,7 @@ template <class FB>
 using wformat =
     typename FB::template add_convention<details::format_dispatch,
                                          details::format_overload_t<wchar_t>>;
-#endif // __STDC_HOSTED__ && __has_include(<format>)
+#endif // __STDC_HOSTED__ && __cpp_lib_format
 
 #if __cpp_rtti >= 199711L
 template <class FB>
@@ -2604,7 +2605,7 @@ struct weak_dispatch : D {
 // == Adapters (std::formatter)                                               ==
 // =============================================================================
 
-#if __STDC_HOSTED__ && __has_include(<format>)
+#if __STDC_HOSTED__ && __cpp_lib_format
 namespace std {
 
 template <pro::v4::facade F, class CharT>
@@ -2635,7 +2636,7 @@ struct formatter<pro::v4::proxy_indirect_accessor<F>, CharT> {
 };
 
 } // namespace std
-#endif // __STDC_HOSTED__ && __has_include(<format>)
+#endif // __STDC_HOSTED__ && __cpp_lib_format
 
 #undef PROD_UNREACHABLE
 #undef PROD_NO_UNIQUE_ADDRESS_ATTRIBUTE

include/proxy/v4/proxy.ixx

@@ -41,10 +41,10 @@ using v4::weak_proxy;
 
 namespace skills {
 
-#if __STDC_HOSTED__ && __has_include(<format>)
+#if __STDC_HOSTED__ && __cpp_lib_format
 using skills::format;
 using skills::wformat;
-#endif // __STDC_HOSTED__ && __has_include(<format>)
+#endif // __STDC_HOSTED__ && __cpp_lib_format
 
 #if __cpp_rtti >= 199711L
 using skills::direct_rtti;
@@ -60,10 +60,10 @@ using skills::slim;
 
 } // namespace pro::inline v4
 
-#if __STDC_HOSTED__ && __has_include(<format>)
+#if __STDC_HOSTED__ && __cpp_lib_format
 export namespace std {
 
 using std::formatter;
 
 } // namespace std
-#endif // __STDC_HOSTED__ && __has_include(<format>)
+#endif // __STDC_HOSTED__ && __cpp_lib_format