diff --git a/libcxx/docs/ReleaseNotes.rst b/libcxx/docs/ReleaseNotes.rst
--- a/libcxx/docs/ReleaseNotes.rst
+++ b/libcxx/docs/ReleaseNotes.rst
@@ -69,6 +69,11 @@
 
 - ``<algorithm>`` no longer includes ``<chrono>`` in any C++ version (it was prevously included in C++17 and earlier).
 
+- ``<string>`` no longer includes ``<vector>`` in any C++ version (it was prevously included in C++20 and earlier).
+
+- ``<string>``, ``<string_view>``, and ``<mutex>`` no longer include ``<functional>``
+  in any C++ version (it was prevously included in C++20 and earlier).
+
 - The headers ``<experimental/algorithm>`` and ``<experimental/functional>`` have been removed, since all the contents
   have been implemented in namespace ``std`` for at least two releases.
 
diff --git a/libcxx/include/mutex b/libcxx/include/mutex
--- a/libcxx/include/mutex
+++ b/libcxx/include/mutex
@@ -715,7 +715,6 @@
 #  include <cstdlib>
 #  include <cstring>
 #  include <ctime>
-#  include <functional>
 #  include <initializer_list>
 #  include <new>
 #  include <stdexcept>
diff --git a/libcxx/include/string b/libcxx/include/string
--- a/libcxx/include/string
+++ b/libcxx/include/string
@@ -4389,13 +4389,11 @@
 #  include <algorithm>
 #  include <concepts>
 #  include <cstdlib>
-#  include <functional>
 #  include <iterator>
 #  include <new>
 #  include <type_traits>
 #  include <typeinfo>
 #  include <utility>
-#  include <vector>
 #endif
 
 #endif // _LIBCPP_STRING
diff --git a/libcxx/include/string_view b/libcxx/include/string_view
--- a/libcxx/include/string_view
+++ b/libcxx/include/string_view
@@ -1047,7 +1047,6 @@
 #  include <algorithm>
 #  include <concepts>
 #  include <cstdlib>
-#  include <functional>
 #  include <iterator>
 #  include <type_traits>
 #endif
diff --git a/libcxx/include/vector b/libcxx/include/vector
--- a/libcxx/include/vector
+++ b/libcxx/include/vector
@@ -293,6 +293,7 @@
 #include <__debug>
 #include <__format/enable_insertable.h>
 #include <__format/formatter.h>
+#include <__format/formatter_bool.h>
 #include <__functional/hash.h>
 #include <__functional/unary_function.h>
 #include <__iterator/advance.h>
@@ -3325,7 +3326,7 @@
 
 #endif // _LIBCPP_STD_VER >= 20
 
-#if _LIBCPP_STD_VER >= 23
+#if !defined(_LIBCPP_HAS_NO_INCOMPLETE_FORMAT) && _LIBCPP_STD_VER >= 23
 template <class _Tp, class CharT>
 // Since is-vector-bool-reference is only used once it's inlined here.
   requires same_as<typename _Tp::__container, vector<bool, typename _Tp::__container::allocator_type>>
@@ -3344,7 +3345,7 @@
         return __underlying_.format(__ref, __ctx);
   }
 };
-#endif // _LIBCPP_STD_VER >= 23
+#endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_FORMAT) && _LIBCPP_STD_VER >= 23
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/test/libcxx/transitive_includes/cxx03.csv b/libcxx/test/libcxx/transitive_includes/cxx03.csv
--- a/libcxx/test/libcxx/transitive_includes/cxx03.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx03.csv
@@ -575,7 +575,6 @@
 mutex cstdlib
 mutex cstring
 mutex ctime
-mutex functional
 mutex initializer_list
 mutex iosfwd
 mutex limits
@@ -805,7 +804,6 @@
 string cstdlib
 string cstring
 string cwchar
-string functional
 string initializer_list
 string iosfwd
 string iterator
@@ -817,7 +815,6 @@
 string type_traits
 string typeinfo
 string utility
-string vector
 string version
 string_view algorithm
 string_view compare
@@ -828,7 +825,6 @@
 string_view cstdlib
 string_view cstring
 string_view cwchar
-string_view functional
 string_view initializer_list
 string_view iosfwd
 string_view iterator
@@ -964,7 +960,9 @@
 variant utility
 variant version
 vector algorithm
+vector array
 vector atomic
+vector cerrno
 vector climits
 vector compare
 vector concepts
@@ -975,8 +973,11 @@
 vector initializer_list
 vector iosfwd
 vector limits
+vector locale
 vector new
 vector stdexcept
+vector string
+vector string_view
 vector tuple
 vector type_traits
 vector typeinfo
diff --git a/libcxx/test/libcxx/transitive_includes/cxx11.csv b/libcxx/test/libcxx/transitive_includes/cxx11.csv
--- a/libcxx/test/libcxx/transitive_includes/cxx11.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx11.csv
@@ -575,7 +575,6 @@
 mutex cstdlib
 mutex cstring
 mutex ctime
-mutex functional
 mutex initializer_list
 mutex iosfwd
 mutex limits
@@ -806,7 +805,6 @@
 string cstdlib
 string cstring
 string cwchar
-string functional
 string initializer_list
 string iosfwd
 string iterator
@@ -818,7 +816,6 @@
 string type_traits
 string typeinfo
 string utility
-string vector
 string version
 string_view algorithm
 string_view compare
@@ -829,7 +826,6 @@
 string_view cstdlib
 string_view cstring
 string_view cwchar
-string_view functional
 string_view initializer_list
 string_view iosfwd
 string_view iterator
@@ -965,7 +961,9 @@
 variant utility
 variant version
 vector algorithm
+vector array
 vector atomic
+vector cerrno
 vector climits
 vector compare
 vector concepts
@@ -976,8 +974,11 @@
 vector initializer_list
 vector iosfwd
 vector limits
+vector locale
 vector new
 vector stdexcept
+vector string
+vector string_view
 vector tuple
 vector type_traits
 vector typeinfo
diff --git a/libcxx/test/libcxx/transitive_includes/cxx14.csv b/libcxx/test/libcxx/transitive_includes/cxx14.csv
--- a/libcxx/test/libcxx/transitive_includes/cxx14.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx14.csv
@@ -577,7 +577,6 @@
 mutex cstdlib
 mutex cstring
 mutex ctime
-mutex functional
 mutex initializer_list
 mutex iosfwd
 mutex limits
@@ -808,7 +807,6 @@
 string cstdlib
 string cstring
 string cwchar
-string functional
 string initializer_list
 string iosfwd
 string iterator
@@ -820,7 +818,6 @@
 string type_traits
 string typeinfo
 string utility
-string vector
 string version
 string_view algorithm
 string_view compare
@@ -831,7 +828,6 @@
 string_view cstdlib
 string_view cstring
 string_view cwchar
-string_view functional
 string_view initializer_list
 string_view iosfwd
 string_view iterator
@@ -967,7 +963,9 @@
 variant utility
 variant version
 vector algorithm
+vector array
 vector atomic
+vector cerrno
 vector climits
 vector compare
 vector concepts
@@ -978,8 +976,11 @@
 vector initializer_list
 vector iosfwd
 vector limits
+vector locale
 vector new
 vector stdexcept
+vector string
+vector string_view
 vector tuple
 vector type_traits
 vector typeinfo
diff --git a/libcxx/test/libcxx/transitive_includes/cxx17.csv b/libcxx/test/libcxx/transitive_includes/cxx17.csv
--- a/libcxx/test/libcxx/transitive_includes/cxx17.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx17.csv
@@ -577,7 +577,6 @@
 mutex cstdlib
 mutex cstring
 mutex ctime
-mutex functional
 mutex initializer_list
 mutex iosfwd
 mutex limits
@@ -808,7 +807,6 @@
 string cstdlib
 string cstring
 string cwchar
-string functional
 string initializer_list
 string iosfwd
 string iterator
@@ -820,7 +818,6 @@
 string type_traits
 string typeinfo
 string utility
-string vector
 string version
 string_view algorithm
 string_view compare
@@ -831,7 +828,6 @@
 string_view cstdlib
 string_view cstring
 string_view cwchar
-string_view functional
 string_view initializer_list
 string_view iosfwd
 string_view iterator
@@ -967,7 +963,9 @@
 variant utility
 variant version
 vector algorithm
+vector array
 vector atomic
+vector cerrno
 vector climits
 vector compare
 vector concepts
@@ -978,8 +976,11 @@
 vector initializer_list
 vector iosfwd
 vector limits
+vector locale
 vector new
 vector stdexcept
+vector string
+vector string_view
 vector tuple
 vector type_traits
 vector typeinfo
diff --git a/libcxx/test/libcxx/transitive_includes/cxx20.csv b/libcxx/test/libcxx/transitive_includes/cxx20.csv
--- a/libcxx/test/libcxx/transitive_includes/cxx20.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx20.csv
@@ -583,7 +583,6 @@
 mutex cstdlib
 mutex cstring
 mutex ctime
-mutex functional
 mutex initializer_list
 mutex iosfwd
 mutex limits
@@ -814,7 +813,6 @@
 string cstdlib
 string cstring
 string cwchar
-string functional
 string initializer_list
 string iosfwd
 string iterator
@@ -826,7 +824,6 @@
 string type_traits
 string typeinfo
 string utility
-string vector
 string version
 string_view algorithm
 string_view compare
@@ -837,7 +834,6 @@
 string_view cstdlib
 string_view cstring
 string_view cwchar
-string_view functional
 string_view initializer_list
 string_view iosfwd
 string_view iterator
@@ -972,7 +968,9 @@
 variant utility
 variant version
 vector algorithm
+vector array
 vector atomic
+vector cerrno
 vector climits
 vector compare
 vector concepts
@@ -983,8 +981,11 @@
 vector initializer_list
 vector iosfwd
 vector limits
+vector locale
 vector new
 vector stdexcept
+vector string
+vector string_view
 vector tuple
 vector type_traits
 vector typeinfo
diff --git a/libcxx/test/libcxx/transitive_includes/cxx2b.csv b/libcxx/test/libcxx/transitive_includes/cxx2b.csv
--- a/libcxx/test/libcxx/transitive_includes/cxx2b.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx2b.csv
@@ -646,15 +646,21 @@
 variant new
 variant tuple
 variant version
+vector array
+vector cerrno
 vector climits
 vector compare
 vector cstddef
 vector cstdint
+vector cstdlib
 vector cstring
 vector initializer_list
 vector iosfwd
 vector limits
+vector locale
 vector new
 vector stdexcept
+vector string
+vector string_view
 vector tuple
 vector version
diff --git a/libcxx/test/std/containers/sequences/vector.bool/vector.bool.fmt/types.compile.pass.cpp b/libcxx/test/std/containers/sequences/vector.bool/vector.bool.fmt/types.compile.pass.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/std/containers/sequences/vector.bool/vector.bool.fmt/types.compile.pass.cpp
@@ -0,0 +1,41 @@
+//===----------------------------------------------------------------------===//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// UNSUPPORTED: libcpp-has-no-incomplete-format
+
+// <vector>
+
+// template<class T, class charT> requires is-vector-bool-reference<T>
+//  struct formatter<T, charT>;
+
+// [format.formatter.spec]/4
+//   If the library provides an explicit or partial specialization of
+//   formatter<T, charT>, that specialization is enabled and meets the
+//   Formatter requirements except as noted otherwise.
+//
+// Tests parts of the BasicFormatter requirements. Like the formattable concept
+// it uses the semiregular concept. It test does not use the formattable
+// concept since it is the intention the formatter is available without
+// including the format header.
+
+// TODO FMT Evaluate what to do with [format.formatter.spec]/2
+// [format.formatter.spec]/2
+//   Each header that declares the template formatter provides the following
+//   enabled specializations:
+// Then there is a list of formatters, but is that really useful?
+// Note this should be discussed in LEWG.
+
+#include <concepts>
+#include <vector>
+
+#include "test_macros.h"
+
+static_assert(std::semiregular<std::formatter<std::vector<bool>::reference, char>>);
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+static_assert(std::semiregular<std::formatter<std::vector<bool>::reference, wchar_t>>);
+#endif