1 files changed, 8 insertions, 17 deletions
diff --git a/libcxx/include/__format/formatter.h b/libcxx/include/__format/formatter.h
index 38b73bba32f3..c39e25b354eb 100644
--- a/libcxx/include/__format/formatter.h
+++ b/libcxx/include/__format/formatter.h
@@ -12,32 +12,27 @@
 
 #include <__algorithm/copy.h>
 #include <__algorithm/fill_n.h>
+#include <__algorithm/transform.h>
+#include <__assert>
 #include <__availability>
+#include <__concepts/same_as.h>
 #include <__config>
 #include <__format/format_error.h>
 #include <__format/format_fwd.h>
 #include <__format/format_string.h>
 #include <__format/parser_std_format_spec.h>
-#include <concepts>
+#include <__utility/move.h>
+#include <__utility/unreachable.h>
 #include <string_view>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 #if _LIBCPP_STD_VER > 17
 
-// TODO FMT Remove this once we require compilers with proper C++20 support.
-// If the compiler has no concepts support, the format header will be disabled.
-// Without concepts support enable_if needs to be used and that too much effort
-// to support compilers with partial C++20 support.
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
-
 /// The default formatter template.
 ///
 /// [format.formatter.spec]/5
@@ -120,7 +115,7 @@ __padding_size(size_t __size, size_t __width,
   size_t __fill = __width - __size;
   switch (__align) {
   case __format_spec::_Flags::_Alignment::__default:
-    _LIBCPP_UNREACHABLE();
+    __libcpp_unreachable();
 
   case __format_spec::_Flags::_Alignment::__left:
     return {0, __fill};
@@ -136,7 +131,7 @@ __padding_size(size_t __size, size_t __width,
   case __format_spec::_Flags::_Alignment::__right:
     return {__fill, 0};
   }
-  _LIBCPP_UNREACHABLE();
+  __libcpp_unreachable();
 }
 
 /**
@@ -279,12 +274,8 @@ __write_unicode(output_iterator<const _CharT&> auto __out_it,
 
 } // namespace __formatter
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
-
 #endif //_LIBCPP_STD_VER > 17
 
 _LIBCPP_END_NAMESPACE_STD
 
-_LIBCPP_POP_MACROS
-
 #endif // _LIBCPP___FORMAT_FORMATTER_H