commit 7fc2b2ace3d3c99097d8175b1eda1eded5dfb44d
author Christopher Di Bella <cjdb@google.com> Sun Mar 21 18:48:24 2021 +0000
committer Copybara-Service <copybara-worker@google.com> Mon Apr 12 11:28:56 2021 -0700
tree 094324566c3833ece39c27c240800d428c7a226f
parent 821c2e174b79c83f91c212cb2c3a0b23e985be12

[libcxx] moves `std::invoke` into `__functional_base`

Including `<concepts>` in other standard library headers (such as
`<iterator>`) creates circular dependencies due to `<functional>`.
Since `<concepts>` only needs `std::invoke` from `<functional>`, the
easiest, fastest, and cleanest way to eliminate the circular dep is to
move `std::invoke` into `__functional_base`.

This has the added advantage of `<concepts>` not transitively importing
`<functional>`.

Differential Revision: https://reviews.llvm.org/D99041

GitOrigin-RevId: c25c22d5f9b7e56c0c350982b5ec41095c5a0a05

include/__functional_base

diff --git a/include/__functional_base b/include/__functional_base
index caa7460..5e98eba 100644
--- a/include/__functional_base
+++ b/include/__functional_base
@@ -665,6 +665,18 @@
 
 #endif  // _LIBCPP_CXX03_LANG
 
+#if _LIBCPP_STD_VER > 14
+
+template <class _Fn, class ..._Args>
+_LIBCPP_CONSTEXPR_AFTER_CXX17 invoke_result_t<_Fn, _Args...>
+invoke(_Fn&& __f, _Args&&... __args)
+    noexcept(is_nothrow_invocable_v<_Fn, _Args...>)
+{
+    return _VSTD::__invoke(_VSTD::forward<_Fn>(__f), _VSTD::forward<_Args>(__args)...);
+}
+
+#endif // _LIBCPP_STD_VER > 14
+
 _LIBCPP_END_NAMESPACE_STD
 
 #endif  // _LIBCPP_FUNCTIONAL_BASE

include/concepts

diff --git a/include/concepts b/include/concepts
index 0a3e927..070e1df 100644
--- a/include/concepts
+++ b/include/concepts
@@ -135,7 +135,7 @@
 */
 
 #include <__config>
-#include <functional>
+#include <__functional_base>
 #include <type_traits>
 #include <utility>
 #include <version>

include/functional

diff --git a/include/functional b/include/functional
index e5b85c2..bbc2301 100644
--- a/include/functional
+++ b/include/functional
@@ -2986,14 +2986,6 @@
 
 #if _LIBCPP_STD_VER > 14
 
-template <class _Fn, class ..._Args>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 invoke_result_t<_Fn, _Args...>
-invoke(_Fn&& __f, _Args&&... __args)
-    noexcept(is_nothrow_invocable_v<_Fn, _Args...>)
-{
-    return _VSTD::__invoke(_VSTD::forward<_Fn>(__f), _VSTD::forward<_Args>(__args)...);
-}
-
 template<class _Op, class _Tuple,
          class _Idxs = typename __make_tuple_indices<tuple_size<_Tuple>::value>::type>
 struct __perfect_forward_impl;