[libc++] Remove <tuple> include from <__format/concepts.h> (#80214)

This also moves `tuple_size_v` into `tuple_size` as a drive-by.

Author: philnik777

libcxx/include/__format/concepts.h

@@ -15,10 +15,12 @@
 #include <__config>
 #include <__format/format_parse_context.h>
 #include <__fwd/format.h>
+#include <__fwd/tuple.h>
+#include <__tuple/tuple_size.h>
 #include <__type_traits/is_specialization.h>
 #include <__type_traits/remove_const.h>
+#include <__type_traits/remove_reference.h>
 #include <__utility/pair.h>
-#include <tuple>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header

libcxx/include/__tuple/tuple_size.h

@@ -43,7 +43,7 @@ struct _LIBCPP_TEMPLATE_VIS tuple_size<__enable_if_tuple_size_imp< volatile _Tp,
 
 template <class _Tp>
 struct _LIBCPP_TEMPLATE_VIS
-    tuple_size<__enable_if_tuple_size_imp< const volatile _Tp, integral_constant<size_t, sizeof(tuple_size<_Tp>)>>>
+    tuple_size<__enable_if_tuple_size_imp<const volatile _Tp, integral_constant<size_t, sizeof(tuple_size<_Tp>)>>>
     : public integral_constant<size_t, tuple_size<_Tp>::value> {};
 
 #else
@@ -63,6 +63,11 @@ struct _LIBCPP_TEMPLATE_VIS tuple_size<tuple<_Tp...> > : public integral_constan
 template <class... _Tp>
 struct _LIBCPP_TEMPLATE_VIS tuple_size<__tuple_types<_Tp...> > : public integral_constant<size_t, sizeof...(_Tp)> {};
 
+#  if _LIBCPP_STD_VER >= 17
+template <class _Tp>
+inline constexpr size_t tuple_size_v = tuple_size<_Tp>::value;
+#  endif
+
 #endif // _LIBCPP_CXX03_LANG
 
 _LIBCPP_END_NAMESPACE_STD

libcxx/include/chrono

@@ -878,6 +878,7 @@ constexpr chrono::year                                  operator ""y(unsigned lo
 #  include <cstring>
 #  include <forward_list>
 #  include <string>
+#  include <tuple>
 #endif
 
 #if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER == 20

libcxx/include/tuple

@@ -1369,9 +1369,6 @@ inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_T1, _T2>::pair(
       second(std::forward<_Args2>(std::get<_I2>(__second_args))...) {}
 
 #  if _LIBCPP_STD_VER >= 17
-template <class _Tp>
-inline constexpr size_t tuple_size_v = tuple_size<_Tp>::value;
-
 #    define _LIBCPP_NOEXCEPT_RETURN(...)                                                                               \
       noexcept(noexcept(__VA_ARGS__)) { return __VA_ARGS__; }
 

libcxx/include/vector

@@ -2990,6 +2990,7 @@ _LIBCPP_POP_MACROS
 #  include <concepts>
 #  include <cstdlib>
 #  include <locale>
+#  include <tuple>
 #  include <type_traits>
 #  include <typeinfo>
 #  include <utility>

libcxx/test/libcxx/transitive_includes/cxx23.csv

@@ -85,7 +85,6 @@ chrono sstream
 chrono stdexcept
 chrono string
 chrono string_view
-chrono tuple
 chrono vector
 chrono version
 cinttypes cstdint

libcxx/test/libcxx/transitive_includes/cxx26.csv

@@ -85,7 +85,6 @@ chrono sstream
 chrono stdexcept
 chrono string
 chrono string_view
-chrono tuple
 chrono vector
 chrono version
 cinttypes cstdint

libcxx/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple_size_v.verify.cpp

@@ -17,8 +17,8 @@
 #include <tuple>
 
 void f() {
-    (void)std::tuple_size_v<std::tuple<> &>; // expected-note {{requested here}}
-    (void)std::tuple_size_v<int>; // expected-note {{requested here}}
-    (void)std::tuple_size_v<std::tuple<>*>; // expected-note {{requested here}}
-    // expected-error@tuple:* 3 {{implicit instantiation of undefined template}}
+  (void)std::tuple_size_v<std::tuple<>&>; // expected-note {{requested here}}
+  (void)std::tuple_size_v<int>;           // expected-note {{requested here}}
+  (void)std::tuple_size_v<std::tuple<>*>; // expected-note {{requested here}}
+                                          // expected-error@*:* 3 {{implicit instantiation of undefined template}}
 }