From 3f3abaf40ad5c732277e0d0be3c0e86b8ba49f34 Mon Sep 17 00:00:00 2001
From: Arthur O'Dwyer <arthur.j.odwyer@gmail.com>
Date: Tue, 15 Feb 2022 16:38:34 -0500
Subject: [PATCH] [libc++] LWG2148, LWG2543: Enable std::hash<Enum> in C++03
 and C++11.

Fixes #49601.

Differential Revision: https://reviews.llvm.org/D119891
---
 libcxx/include/__functional/hash.h                           | 5 +----
 .../std/utilities/function.objects/unord.hash/enum.pass.cpp  | 5 +----
 .../utilities/function.objects/unord.hash/non_enum.pass.cpp  | 2 +-
 libcxx/test/support/poisoned_hash_helper.h                   | 4 ----
 4 files changed, 3 insertions(+), 13 deletions(-)

diff --git a/libcxx/include/__functional/hash.h b/libcxx/include/__functional/hash.h
index 61b87617db8ff..2b3b96e534216 100644
--- a/libcxx/include/__functional/hash.h
+++ b/libcxx/include/__functional/hash.h
@@ -781,8 +781,6 @@ struct _LIBCPP_TEMPLATE_VIS hash<long double>
     }
 };
 
-#if _LIBCPP_STD_VER > 11
-
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 template <class _Tp, bool = is_enum<_Tp>::value>
 struct _LIBCPP_TEMPLATE_VIS __enum_hash
@@ -799,7 +797,7 @@ _LIBCPP_SUPPRESS_DEPRECATED_POP
     size_t operator()(_Tp __v) const _NOEXCEPT
     {
         typedef typename underlying_type<_Tp>::type type;
-        return hash<type>{}(static_cast<type>(__v));
+        return hash<type>()(static_cast<type>(__v));
     }
 };
 template <class _Tp>
@@ -813,7 +811,6 @@ template <class _Tp>
 struct _LIBCPP_TEMPLATE_VIS hash : public __enum_hash<_Tp>
 {
 };
-#endif
 
 #if _LIBCPP_STD_VER > 14
 
diff --git a/libcxx/test/std/utilities/function.objects/unord.hash/enum.pass.cpp b/libcxx/test/std/utilities/function.objects/unord.hash/enum.pass.cpp
index 4aece56b72117..6dd14dc77496a 100644
--- a/libcxx/test/std/utilities/function.objects/unord.hash/enum.pass.cpp
+++ b/libcxx/test/std/utilities/function.objects/unord.hash/enum.pass.cpp
@@ -8,12 +8,9 @@
 
 // ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
 
-// UNSUPPORTED: c++03, c++11
-
 // <functional>
 
-// make sure that we can hash enumeration values
-// Not very portable
+// Make sure that we can hash enumeration values.
 
 #include "test_macros.h"
 
diff --git a/libcxx/test/std/utilities/function.objects/unord.hash/non_enum.pass.cpp b/libcxx/test/std/utilities/function.objects/unord.hash/non_enum.pass.cpp
index 85fed02190661..94cc9d912f3a7 100644
--- a/libcxx/test/std/utilities/function.objects/unord.hash/non_enum.pass.cpp
+++ b/libcxx/test/std/utilities/function.objects/unord.hash/non_enum.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03, c++11
+// UNSUPPORTED: c++03
 
 // <functional>
 
diff --git a/libcxx/test/support/poisoned_hash_helper.h b/libcxx/test/support/poisoned_hash_helper.h
index 9df349656da96..a0271e4af1e44 100644
--- a/libcxx/test/support/poisoned_hash_helper.h
+++ b/libcxx/test/support/poisoned_hash_helper.h
@@ -79,12 +79,8 @@ using LibraryHashTypes = TypeList<
       float,
       double,
       long double,
-#if TEST_STD_VER >= 14
-      // Enum types
       PoisonedHashDetail::Enum,
       PoisonedHashDetail::EnumClass,
-#endif
-      // pointer types
       void*,
       void const*,
       PoisonedHashDetail::Class*