From 34d878c7bc86d42fd973ad82ed76759ad423ed88 Mon Sep 17 00:00:00 2001
From: Thomas Rodgers <trodgers@redhat.com>
Date: Tue, 21 May 2019 22:15:00 +0000
Subject: [PATCH] LWG 3062 - Unnecessary decay_t in is_execution_policy_v

    * include/pstl/execution_defs.h (__enable_if_execution_policy):
    Use std::__remove_cvref_t when building with GCC.

From-SVN: r271489
---
 libstdc++-v3/ChangeLog                     | 6 ++++++
 libstdc++-v3/include/pstl/execution_defs.h | 6 ++++++
 2 files changed, 12 insertions(+)

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 804bace5e03..056e35447de 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,9 @@
+2019-05-21  Thomas Rodgers  <trodgers@redhat.com>
+
+	LWG 3062 - Unnecessary decay_t in is_execution_policy_v
+	* include/pstl/execution_defs.h (__enable_if_execution_policy):
+	Use std::__remove_cvref_t when building with GCC.
+
 2019-05-21  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR libstdc++/90252
diff --git a/libstdc++-v3/include/pstl/execution_defs.h b/libstdc++-v3/include/pstl/execution_defs.h
index 1a551c7871c..34b0e3d6350 100644
--- a/libstdc++-v3/include/pstl/execution_defs.h
+++ b/libstdc++-v3/include/pstl/execution_defs.h
@@ -152,9 +152,15 @@ constexpr bool is_execution_policy_v = __pstl::execution::is_execution_policy<_T
 namespace __internal
 {
 template <class _ExecPolicy, class _Tp>
+#if _GLIBCXX_RELEASE >= 9
+using __enable_if_execution_policy =
+    typename std::enable_if<__pstl::execution::is_execution_policy<std::__remove_cvref_t<_ExecPolicy>>::value,
+                            _Tp>::type;
+#else
 using __enable_if_execution_policy =
     typename std::enable_if<__pstl::execution::is_execution_policy<typename std::decay<_ExecPolicy>::type>::value,
                             _Tp>::type;
+#endif
 } // namespace __internal
 
 } // namespace __pstl
-- 
2.30.2