diff --git a/libcxx/include/__config b/libcxx/include/__config
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -1199,13 +1199,15 @@
 #    endif
 #  endif
 
-// There are a handful of standard library types that are intended to support CTAD but don't need any
-// explicit deduction guides to do so. This macro is used to mark them as such, which suppresses the
-// '-Wctad-maybe-unsupported' compiler warning when CTAD is used in user code with these classes.
+// There are a handful of public standard library types that are intended to
+// support CTAD but don't need any explicit deduction guides to do so. This
+// macro is used to mark them as such, which suppresses the
+// '-Wctad-maybe-unsupported' compiler warning when CTAD is used in user code
+// with these classes.
 #if _LIBCPP_STD_VER >= 17
-#  define _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(_ClassName)                                                                  \
-    template <class _Tag = void>                                                                                       \
-    _ClassName(typename _Tag::__allow_ctad) -> _ClassName<_Tag>
+#    define _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(_ClassName)                                                                \
+      template <class ..._Tag>                                                                                         \
+      _ClassName(typename _Tag::__allow_ctad...) -> _ClassName<_Tag...>
 #else
 #  define _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(_ClassName) static_assert(true, "")
 #endif
diff --git a/libcxx/include/__format/format_context.h b/libcxx/include/__format/format_context.h
--- a/libcxx/include/__format/format_context.h
+++ b/libcxx/include/__format/format_context.h
@@ -50,8 +50,7 @@
     _OutIt __out_it,
     basic_format_args<basic_format_context<_OutIt, _CharT>> __args,
     optional<_VSTD::locale>&& __loc = nullopt) {
-  return _VSTD::basic_format_context<_OutIt, _CharT>(_VSTD::move(__out_it), __args,
-                                                     _VSTD::move(__loc));
+  return _VSTD::basic_format_context(_VSTD::move(__out_it), __args, _VSTD::move(__loc));
 }
 #else
 template <class _OutIt, class _CharT>
@@ -59,7 +58,7 @@
 __format_context_create(
     _OutIt __out_it,
     basic_format_args<basic_format_context<_OutIt, _CharT>> __args) {
-  return _VSTD::basic_format_context<_OutIt, _CharT>(_VSTD::move(__out_it), __args);
+  return _VSTD::basic_format_context(_VSTD::move(__out_it), __args);
 }
 #endif
 
@@ -143,6 +142,7 @@
       : __out_it_(_VSTD::move(__out_it)), __args_(__args) {}
 #endif
 };
+_LIBCPP_CTAD_SUPPORTED_FOR_TYPE(basic_format_context);
 
 #endif //_LIBCPP_STD_VER > 17
 
diff --git a/libcxx/include/__format/format_functions.h b/libcxx/include/__format/format_functions.h
--- a/libcxx/include/__format/format_functions.h
+++ b/libcxx/include/__format/format_functions.h
@@ -239,8 +239,7 @@
 _LIBCPP_HIDE_FROM_ABI constexpr const _CharT*
 __handle_replacement_field(const _CharT* __begin, const _CharT* __end,
                            _ParseCtx& __parse_ctx, _Ctx& __ctx) {
-  __format::__parse_number_result<_CharT> __r =
-      __format::__parse_arg_id(__begin, __end, __parse_ctx);
+  __format::__parse_number_result __r = __format::__parse_arg_id(__begin, __end, __parse_ctx);
 
   bool __parse = *__r.__ptr == _CharT(':');
   switch (*__r.__ptr) {
@@ -392,15 +391,12 @@
         _OutIt __out_it, basic_string_view<_CharT> __fmt,
         basic_format_args<basic_format_context<_FormatOutIt, _CharT>> __args) {
   if constexpr (same_as<_OutIt, _FormatOutIt>)
-    return _VSTD::__format::__vformat_to(
-        basic_format_parse_context<_CharT>{__fmt, __args.__size()},
-        _VSTD::__format_context_create(_VSTD::move(__out_it), __args));
+    return _VSTD::__format::__vformat_to(basic_format_parse_context{__fmt, __args.__size()},
+                                         _VSTD::__format_context_create(_VSTD::move(__out_it), __args));
   else {
     __format::__format_buffer<_OutIt, _CharT> __buffer{_VSTD::move(__out_it)};
-    _VSTD::__format::__vformat_to(
-        basic_format_parse_context<_CharT>{__fmt, __args.__size()},
-        _VSTD::__format_context_create(__buffer.__make_output_iterator(),
-                                       __args));
+    _VSTD::__format::__vformat_to(basic_format_parse_context{__fmt, __args.__size()},
+                                  _VSTD::__format_context_create(__buffer.__make_output_iterator(), __args));
     return _VSTD::move(__buffer).__out_it();
   }
 }
@@ -473,7 +469,7 @@
                                                                 basic_string_view<_CharT> __fmt,
                                                                 basic_format_args<_Context> __args) {
   __format::__format_to_n_buffer<_OutIt, _CharT> __buffer{_VSTD::move(__out_it), __n};
-  _VSTD::__format::__vformat_to(basic_format_parse_context<_CharT>{__fmt, __args.__size()},
+  _VSTD::__format::__vformat_to(basic_format_parse_context{__fmt, __args.__size()},
                                 _VSTD::__format_context_create(__buffer.__make_output_iterator(), __args));
   return _VSTD::move(__buffer).__result();
 }
@@ -496,7 +492,7 @@
 template <class _CharT>
 _LIBCPP_HIDE_FROM_ABI size_t __vformatted_size(basic_string_view<_CharT> __fmt, auto __args) {
   __format::__formatted_size_buffer<_CharT> __buffer;
-  _VSTD::__format::__vformat_to(basic_format_parse_context<_CharT>{__fmt, __args.__size()},
+  _VSTD::__format::__vformat_to(basic_format_parse_context{__fmt, __args.__size()},
                                 _VSTD::__format_context_create(__buffer.__make_output_iterator(), __args));
   return _VSTD::move(__buffer).__result();
 }
@@ -524,15 +520,13 @@
         basic_format_args<basic_format_context<_FormatOutIt, _CharT>> __args) {
   if constexpr (same_as<_OutIt, _FormatOutIt>)
     return _VSTD::__format::__vformat_to(
-        basic_format_parse_context<_CharT>{__fmt, __args.__size()},
-        _VSTD::__format_context_create(_VSTD::move(__out_it), __args,
-                                       _VSTD::move(__loc)));
+        basic_format_parse_context{__fmt, __args.__size()},
+        _VSTD::__format_context_create(_VSTD::move(__out_it), __args, _VSTD::move(__loc)));
   else {
     __format::__format_buffer<_OutIt, _CharT> __buffer{_VSTD::move(__out_it)};
     _VSTD::__format::__vformat_to(
-        basic_format_parse_context<_CharT>{__fmt, __args.__size()},
-        _VSTD::__format_context_create(__buffer.__make_output_iterator(),
-                                       __args, _VSTD::move(__loc)));
+        basic_format_parse_context{__fmt, __args.__size()},
+        _VSTD::__format_context_create(__buffer.__make_output_iterator(), __args, _VSTD::move(__loc)));
     return _VSTD::move(__buffer).__out_it();
   }
 }
@@ -610,7 +604,7 @@
                                                                 basic_format_args<_Context> __args) {
   __format::__format_to_n_buffer<_OutIt, _CharT> __buffer{_VSTD::move(__out_it), __n};
   _VSTD::__format::__vformat_to(
-      basic_format_parse_context<_CharT>{__fmt, __args.__size()},
+      basic_format_parse_context{__fmt, __args.__size()},
       _VSTD::__format_context_create(__buffer.__make_output_iterator(), __args, _VSTD::move(__loc)));
   return _VSTD::move(__buffer).__result();
 }
@@ -637,7 +631,7 @@
 _LIBCPP_HIDE_FROM_ABI size_t __vformatted_size(locale __loc, basic_string_view<_CharT> __fmt, auto __args) {
   __format::__formatted_size_buffer<_CharT> __buffer;
   _VSTD::__format::__vformat_to(
-      basic_format_parse_context<_CharT>{__fmt, __args.__size()},
+      basic_format_parse_context{__fmt, __args.__size()},
       _VSTD::__format_context_create(__buffer.__make_output_iterator(), __args, _VSTD::move(__loc)));
   return _VSTD::move(__buffer).__result();
 }
diff --git a/libcxx/include/__format/format_parse_context.h b/libcxx/include/__format/format_parse_context.h
--- a/libcxx/include/__format/format_parse_context.h
+++ b/libcxx/include/__format/format_parse_context.h
@@ -88,6 +88,7 @@
   size_t __next_arg_id_;
   size_t __num_args_;
 };
+_LIBCPP_CTAD_SUPPORTED_FOR_TYPE(basic_format_parse_context);
 
 using format_parse_context = basic_format_parse_context<char>;
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
diff --git a/libcxx/include/__format/format_string.h b/libcxx/include/__format/format_string.h
--- a/libcxx/include/__format/format_string.h
+++ b/libcxx/include/__format/format_string.h
@@ -32,6 +32,9 @@
   uint32_t __value;
 };
 
+template <class _CharT>
+__parse_number_result(const _CharT*, uint32_t) -> __parse_number_result<_CharT>;
+
 template <class _CharT>
 _LIBCPP_HIDE_FROM_ABI constexpr __parse_number_result<_CharT>
 __parse_number(const _CharT* __begin, const _CharT* __end);
diff --git a/libcxx/include/__format/parser_std_format_spec.h b/libcxx/include/__format/parser_std_format_spec.h
--- a/libcxx/include/__format/parser_std_format_spec.h
+++ b/libcxx/include/__format/parser_std_format_spec.h
@@ -54,8 +54,7 @@
   if (__begin == __end)
     __throw_format_error("End of input while parsing format-spec arg-id");
 
-  __format::__parse_number_result<_CharT> __r =
-      __format::__parse_arg_id(__begin, __end, __parse_ctx);
+  __format::__parse_number_result __r = __format::__parse_arg_id(__begin, __end, __parse_ctx);
 
   if (__r.__ptr == __end || *__r.__ptr != _CharT('}'))
     __throw_format_error("Invalid arg-id");
@@ -422,7 +421,7 @@
       __throw_format_error("A format-spec width field shouldn't have a leading zero");
 
     if (*__begin == _CharT('{')) {
-      __format::__parse_number_result<_CharT> __r = __format_spec::__parse_arg_id(++__begin, __end, __parse_ctx);
+      __format::__parse_number_result __r = __format_spec::__parse_arg_id(++__begin, __end, __parse_ctx);
       __width_as_arg_ = true;
       __width_ = __r.__value;
       __begin = __r.__ptr;
@@ -432,7 +431,7 @@
     if (*__begin < _CharT('0') || *__begin > _CharT('9'))
       return false;
 
-    __format::__parse_number_result<_CharT> __r = __format::__parse_number(__begin, __end);
+    __format::__parse_number_result __r = __format::__parse_number(__begin, __end);
     __width_ = __r.__value;
     _LIBCPP_ASSERT(__width_ != 0, "A zero value isn't allowed and should be impossible, "
                                   "due to validations in this function");
@@ -450,7 +449,7 @@
       __throw_format_error("End of input while parsing format-spec precision");
 
     if (*__begin == _CharT('{')) {
-      __format::__parse_number_result<_CharT> __arg_id = __format_spec::__parse_arg_id(++__begin, __end, __parse_ctx);
+      __format::__parse_number_result __arg_id = __format_spec::__parse_arg_id(++__begin, __end, __parse_ctx);
       __precision_as_arg_ = true;
       __precision_ = __arg_id.__value;
       __begin = __arg_id.__ptr;
@@ -460,7 +459,7 @@
     if (*__begin < _CharT('0') || *__begin > _CharT('9'))
       __throw_format_error("The format-spec precision field doesn't contain a value or arg-id");
 
-    __format::__parse_number_result<_CharT> __r = __format::__parse_number(__begin, __end);
+    __format::__parse_number_result __r = __format::__parse_number(__begin, __end);
     __precision_ = __r.__value;
     __precision_as_arg_ = false;
     __begin = __r.__ptr;
@@ -702,6 +701,9 @@
   const _CharT* __last_;
 };
 
+template <class _CharT>
+__column_width_result(size_t, const _CharT*) -> __column_width_result<_CharT>;
+
 /// Since a column width can be two it's possible that the requested column
 /// width can't be achieved. Depending on the intended usage the policy can be
 /// selected.
@@ -879,7 +881,7 @@
   }
 
   ptrdiff_t __ascii_size = __it - __str.begin();
-  __column_width_result<_CharT> __result =
+  __column_width_result __result =
       __detail::__estimate_column_width_grapheme_clustering(__it, __str.end(), __maximum, __rounding);
 
   __result.__width_ += __ascii_size;
diff --git a/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/advance_to.pass.cpp b/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/advance_to.pass.cpp
--- a/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/advance_to.pass.cpp
+++ b/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/advance_to.pass.cpp
@@ -24,8 +24,7 @@
     std::basic_format_args<std::basic_format_context<OutIt, CharT>> args) {
   {
     std::basic_string<CharT> str[3];
-    std::basic_format_context<OutIt, CharT> context =
-        test_format_context_create(OutIt{str[0]}, args);
+    std::basic_format_context context = test_format_context_create(OutIt{str[0]}, args);
     context.out() = CharT('a');
     context.advance_to(OutIt{str[1]});
     context.out() = CharT('b');
diff --git a/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/arg.pass.cpp b/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/arg.pass.cpp
--- a/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/arg.pass.cpp
+++ b/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/arg.pass.cpp
@@ -28,8 +28,7 @@
   std::basic_format_args args = store;
 
   std::basic_string<CharT> output;
-  const std::basic_format_context<OutIt, CharT> context =
-      test_format_context_create(OutIt{output}, args);
+  const std::basic_format_context context = test_format_context_create(OutIt{output}, args);
   LIBCPP_ASSERT(args.__size() == 4);
   ASSERT_NOEXCEPT(context.arg(0));
   for (size_t i = 0, e = args.__size(); i != e; ++i) {
diff --git a/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/ctor.pass.cpp b/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/ctor.pass.cpp
--- a/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/ctor.pass.cpp
+++ b/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/ctor.pass.cpp
@@ -55,7 +55,7 @@
   {
     std::basic_string<CharT> output;
     OutIt out_it{output};
-    std::basic_format_context<OutIt, CharT> context = test_format_context_create(out_it, args);
+    std::basic_format_context context = test_format_context_create(out_it, args);
     LIBCPP_ASSERT(args.__size() == 4);
 
     assert(test_basic_format_arg(context.arg(0), true));
@@ -79,7 +79,7 @@
   {
     std::basic_string<CharT> output;
     OutIt out_it{output};
-    std::basic_format_context<OutIt, CharT> context = test_format_context_create(out_it, args, en_US);
+    std::basic_format_context context = test_format_context_create(out_it, args, en_US);
 
     LIBCPP_ASSERT(args.__size() == 4);
     assert(test_basic_format_arg(context.arg(0), true));
@@ -99,7 +99,7 @@
   {
     std::basic_string<CharT> output;
     OutIt out_it{output};
-    std::basic_format_context<OutIt, CharT> context = test_format_context_create(out_it, args, fr_FR);
+    std::basic_format_context context = test_format_context_create(out_it, args, fr_FR);
 
     LIBCPP_ASSERT(args.__size() == 4);
     assert(test_basic_format_arg(context.arg(0), true));
diff --git a/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/locale.pass.cpp b/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/locale.pass.cpp
--- a/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/locale.pass.cpp
+++ b/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/locale.pass.cpp
@@ -39,7 +39,7 @@
   {
     std::basic_string<CharT> output;
     OutIt out_it{output};
-    std::basic_format_context<OutIt, CharT> context = test_format_context_create(out_it, args, en_US);
+    std::basic_format_context context = test_format_context_create(out_it, args, en_US);
     assert(args.__size() == 4);
     assert(test_basic_format_arg(context.arg(0), true));
     assert(test_basic_format_arg(context.arg(1), CharT('a')));
@@ -58,7 +58,7 @@
   {
     std::basic_string<CharT> output;
     OutIt out_it{output};
-    std::basic_format_context<OutIt, CharT> context = test_format_context_create(out_it, args, fr_FR);
+    std::basic_format_context context = test_format_context_create(out_it, args, fr_FR);
     assert(args.__size() == 4);
     assert(test_basic_format_arg(context.arg(0), true));
     assert(test_basic_format_arg(context.arg(1), CharT('a')));
diff --git a/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/out.pass.cpp b/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/out.pass.cpp
--- a/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/out.pass.cpp
+++ b/libcxx/test/std/utilities/format/format.formatter/format.context/format.context/out.pass.cpp
@@ -25,7 +25,7 @@
   {
     std::basic_string<CharT> str;
     OutIt out_it{str};
-    std::basic_format_context<OutIt, CharT> context = test_format_context_create(out_it, args);
+    std::basic_format_context context = test_format_context_create(out_it, args);
     context.out() = CharT('a');
     context.out() = CharT('b');
     context.out() = CharT('c');
diff --git a/libcxx/test/std/utilities/format/format.formatter/format.parse.ctx/advance_to.pass.cpp b/libcxx/test/std/utilities/format/format.formatter/format.parse.ctx/advance_to.pass.cpp
--- a/libcxx/test/std/utilities/format/format.formatter/format.parse.ctx/advance_to.pass.cpp
+++ b/libcxx/test/std/utilities/format/format.formatter/format.parse.ctx/advance_to.pass.cpp
@@ -35,7 +35,7 @@
   }
   {
     std::basic_string_view view{fmt};
-    std::basic_format_parse_context<CharT> context(view);
+    std::basic_format_parse_context context(view);
 
     context.advance_to(context.begin() + 1);
     assert(std::to_address(context.begin()) == fmt + 1);
diff --git a/libcxx/test/std/utilities/format/format.formatter/format.parse.ctx/begin.pass.cpp b/libcxx/test/std/utilities/format/format.formatter/format.parse.ctx/begin.pass.cpp
--- a/libcxx/test/std/utilities/format/format.formatter/format.parse.ctx/begin.pass.cpp
+++ b/libcxx/test/std/utilities/format/format.formatter/format.parse.ctx/begin.pass.cpp
@@ -28,7 +28,7 @@
   }
   {
     std::basic_string_view view{fmt};
-    std::basic_format_parse_context<CharT> context(view);
+    std::basic_format_parse_context context(view);
     assert(context.begin() == view.begin());
     ASSERT_NOEXCEPT(context.begin());
   }
diff --git a/libcxx/test/std/utilities/format/format.formatter/format.parse.ctx/ctor.pass.cpp b/libcxx/test/std/utilities/format/format.formatter/format.parse.ctx/ctor.pass.cpp
--- a/libcxx/test/std/utilities/format/format.formatter/format.parse.ctx/ctor.pass.cpp
+++ b/libcxx/test/std/utilities/format/format.formatter/format.parse.ctx/ctor.pass.cpp
@@ -39,10 +39,8 @@
   static_assert(
       !std::is_move_assignable_v<std::basic_format_parse_context<CharT> >);
 
-  ASSERT_NOEXCEPT(
-      std::basic_format_parse_context<CharT>{std::basic_string_view<CharT>{}});
-  ASSERT_NOEXCEPT(
-      std::basic_format_parse_context<CharT>{std::basic_string_view<CharT>{}, 42});
+  ASSERT_NOEXCEPT(std::basic_format_parse_context{std::basic_string_view<CharT>{}});
+  ASSERT_NOEXCEPT(std::basic_format_parse_context{std::basic_string_view<CharT>{}, 42});
 
   {
     std::basic_format_parse_context<CharT> context(fmt);
@@ -51,7 +49,7 @@
   }
   {
     std::basic_string_view view{fmt};
-    std::basic_format_parse_context<CharT> context(view);
+    std::basic_format_parse_context context(view);
     assert(context.begin() == view.begin());
     assert(context.end() == view.end());
   }
diff --git a/libcxx/test/std/utilities/format/format.formatter/format.parse.ctx/end.pass.cpp b/libcxx/test/std/utilities/format/format.formatter/format.parse.ctx/end.pass.cpp
--- a/libcxx/test/std/utilities/format/format.formatter/format.parse.ctx/end.pass.cpp
+++ b/libcxx/test/std/utilities/format/format.formatter/format.parse.ctx/end.pass.cpp
@@ -28,7 +28,7 @@
   }
   {
     std::basic_string_view view{fmt};
-    std::basic_format_parse_context<CharT> context(view);
+    std::basic_format_parse_context context(view);
     assert(context.end() == view.end());
     ASSERT_NOEXCEPT(context.end());
   }