[libcxx-commits] [PATCH] D114624: [pstl] Fix incorrect usage of std::invoke_result

[Ruslan Arutyunyan via Phabricator via libcxx-commits]

rarutyun created this revision.
rarutyun added reviewers: ldionne, MikeDvorskiy, Quuxplusone.
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`std::invoke_result` takes function object type and arguments separately (unlike `std::result_of`) so, `std::invoke_result_t<F()>` usage is incorrect.

On the other hand, we don't need `std::invoke()` semantics here at all. So just simplifying the code without extra dependency and use trailing return type as the fix.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D114624

Files:
  pstl/include/pstl/internal/utils.h


Index: pstl/include/pstl/internal/utils.h
===================================================================
--- pstl/include/pstl/internal/utils.h
+++ pstl/include/pstl/internal/utils.h
@@ -63,15 +63,15 @@
 }
 
 template <typename _F1, typename _F2>
-typename std::invoke_result<_F1()>::type
-__invoke_if_else(std::true_type, _F1 __f1, _F2)
+auto
+__invoke_if_else(std::true_type, _F1 __f1, _F2) -> decltype(__f1())
 {
     return __f1();
 }
 
 template <typename _F1, typename _F2>
-typename std::invoke_result<_F2()>::type
-__invoke_if_else(std::false_type, _F1, _F2 __f2)
+auto
+__invoke_if_else(std::false_type, _F1, _F2 __f2) -> decltype(__f2())
 {
     return __f2();
 }


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