[libc++] Granularize <type_traits> includes in <bit>, <numbers> and <coroutine>

[philnik]

Summary

<coroutine> seems to be new enough to not be a huge problem.

[Mordante]

LGTM after coroutines is fixed.

libcxx/test/libcxx/transitive_includes/cxx20.csv

186 ↗

(On Diff #485012)

I really prefer not the breaks existing language versions unless we need to. Even when this header is new, its predecessor in experimental has been around longer. So this might break more than just new users.

[philnik]

libcxx/test/libcxx/transitive_includes/cxx20.csv

186 ↗

(On Diff #485012)

We also removed includes from <ranges> and <format> because they were still experimental. <coroutine> isn't experimental anymore, but I don't think a lot of people have started using it. We've got it for just two releases now. Also, if people switch over from the experimental version they have to touch the includes anyways.

[philnik]

Don't remove includes in older versions

libcxx/include/__coroutine/coroutine_handle.h

 //===----------------------------------------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP___COROUTINE_COROUTINE_HANDLE_H
 #define _LIBCPP___COROUTINE_COROUTINE_HANDLE_H
 
 #include <__assert>
 #include <__config>
 #include <__functional/hash.h>
 #include <__memory/addressof.h>
+#include <__type_traits/remove_cv.h>
 #include <compare>
-#include <type_traits>
+#include <cstddef>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 #if _LIBCPP_STD_VER > 17
 
 _LIBCPP_BEGIN_NAMESPACE_STD

libcxx/include/__coroutine/coroutine_traits.h

 //===----------------------------------------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP___COROUTINE_COROUTINE_TRAITS_H
 #define _LIBCPP___COROUTINE_COROUTINE_TRAITS_H
 
 #include <__config>
-#include <type_traits>
+#include <__type_traits/void_t.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 #if _LIBCPP_STD_VER > 17
 
 _LIBCPP_BEGIN_NAMESPACE_STD

libcxx/include/__numeric/gcd_lcm.h

 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP___NUMERIC_GCD_LCM_H
 #define _LIBCPP___NUMERIC_GCD_LCM_H
 
 #include <__assert>
 #include <__config>
+#include <__type_traits/common_type.h>
+#include <__type_traits/is_integral.h>
+#include <__type_traits/is_same.h>
+#include <__type_traits/is_signed.h>
+#include <__type_traits/make_unsigned.h>
 #include <limits>
-#include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>
 

libcxx/include/__numeric/midpoint.h

 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP___NUMERIC_MIDPOINT_H
 #define _LIBCPP___NUMERIC_MIDPOINT_H
 
 #include <__config>
+#include <__type_traits/enable_if.h>
+#include <__type_traits/is_floating_point.h>
+#include <__type_traits/is_integral.h>
+#include <__type_traits/is_null_pointer.h>
+#include <__type_traits/is_object.h>
+#include <__type_traits/is_pointer.h>
+#include <__type_traits/is_same.h>
+#include <__type_traits/is_void.h>
+#include <__type_traits/make_unsigned.h>
+#include <__type_traits/remove_pointer.h>
+#include <cstddef>
 #include <limits>
-#include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>
 

libcxx/include/coroutine

 #include <compare>
 
 #ifndef _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER
 #  pragma GCC system_header
 #endif
 
 #if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
 #  include <iosfwd>
+#  include <type_traits>
 #endif
 
 #endif // _LIBCPP_COROUTINE

libcxx/include/numbers

namespace std::numbers {
   inline constexpr double egamma     = egamma_v<double>;
   inline constexpr double phi        = phi_v<double>;
 }
 */
 
 #include <__assert> // all public C++ headers provide the assertion handler
 #include <__concepts/arithmetic.h>
 #include <__config>
-#include <type_traits>
 #include <version>
 
 #if _LIBCPP_STD_VER > 17
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 

 } // namespace numbers
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP_STD_VER > 17
 
 #if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
 #  include <concepts>
+#  include <type_traits>
 #endif
 
 #endif // _LIBCPP_NUMBERS

libcxx/include/numeric

 #if defined(_LIBCPP_HAS_PARALLEL_ALGORITHMS) && _LIBCPP_STD_VER >= 17
 #   include <__pstl_numeric>
 #endif
 
 #if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
 #  include <concepts>
 #  include <functional>
 #  include <iterator>
+#  include <type_traits>
 #endif
 
 #endif // _LIBCPP_NUMERIC

libcxx/test/libcxx/transitive_includes/cxx2b.csv

 condition_variable system_error
 condition_variable typeinfo
 condition_variable version
 coroutine compare
 coroutine cstddef
 coroutine cstdint
 coroutine cstring
 coroutine limits
-coroutine type_traits
 coroutine version
 cstddef version
 ctgmath ccomplex
 ctgmath cmath
 cwchar cwctype
 cwctype cctype
 deque compare
 deque cstddef

 mutex system_error
 mutex tuple
 mutex typeinfo
 mutex version
 new cstddef
 new cstdlib
 new exception
 new version
-numbers type_traits
 numbers version
 numeric cmath
 numeric cstddef
 numeric limits
-numeric type_traits
 numeric version
 optional compare
 optional cstddef
 optional cstdint
 optional cstring
 optional initializer_list
 optional limits
 optional new

libcxx/test/std/numerics/bit/bit.pow.two/bit_ceil.fail.cpp

 //          T is an unsigned integer type
 
 #include <bit>
 #include <cassert>
 #include <cstddef>
 #include <cstdint>
 #include <limits>
 
-#include "test_macros.h"
-
 class A{};
 enum       E1 : unsigned char { rEd };
 enum class E2 : unsigned char { red };
 
 template <typename T>
 constexpr bool toobig()
 {
     return 0 == std::bit_ceil(std::numeric_limits<T>::max());