[libcxx-commits] [libcxx] Revert "[libc++] Use _If for conditional_t" (PR #96843)

[via libcxx-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-libcxx

Author: James Y Knight (jyknight)

<details>
<summary>Changes</summary>

Reverts llvm/llvm-project#<!-- -->96193

---
Full diff: https://github.com/llvm/llvm-project/pull/96843.diff


1 Files Affected:

- (modified) libcxx/include/__type_traits/conditional.h (+5-4) 


``````````diff
diff --git a/libcxx/include/__type_traits/conditional.h b/libcxx/include/__type_traits/conditional.h
index 7d5849ee824e3..5b5445a837427 100644
--- a/libcxx/include/__type_traits/conditional.h
+++ b/libcxx/include/__type_traits/conditional.h
@@ -44,14 +44,15 @@ struct _LIBCPP_TEMPLATE_VIS conditional<false, _If, _Then> {
   using type _LIBCPP_NODEBUG = _Then;
 };
 
-template <bool _Bp, class _IfRes, class _ElseRes>
-using __conditional_t _LIBCPP_NODEBUG = _If<_Bp, _IfRes, _ElseRes>;
-
 #if _LIBCPP_STD_VER >= 14
 template <bool _Bp, class _IfRes, class _ElseRes>
-using conditional_t _LIBCPP_NODEBUG = __conditional_t<_Bp, _IfRes, _ElseRes>;
+using conditional_t _LIBCPP_NODEBUG = typename conditional<_Bp, _IfRes, _ElseRes>::type;
 #endif
 
+// Helper so we can use "conditional_t" in all language versions.
+template <bool _Bp, class _If, class _Then>
+using __conditional_t _LIBCPP_NODEBUG = typename conditional<_Bp, _If, _Then>::type;
+
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___TYPE_TRAITS_CONDITIONAL_H

``````````

</details>


https://github.com/llvm/llvm-project/pull/96843