[gcc/devel/omp/gcc-9] Add parens around constraint in <memory>.

[Tobias Burnus]

https://gcc.gnu.org/g:2f1b34f9ffcbb94ac0ca60c79dabc5c20fc6fc11

commit 2f1b34f9ffcbb94ac0ca60c79dabc5c20fc6fc11
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Jul 26 14:36:39 2019 +0100

    Add parens around constraint in <memory>.
    
    C++20 concepts require parens around atomic constraints that are not
    primary-expressions.
    
    Backport from mainline
    2019-07-16  Jason Merrill  <jason@redhat.com>
    
    	* include/std/memory (uses_allocator_construction_args): Add parens
    	around constraint.
    
    From-SVN: r273833

Diff:
---
 libstdc++-v3/ChangeLog          | 8 ++++++++
 libstdc++-v3/include/std/memory | 2 +-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index d60df17..e68a43c 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,6 +1,14 @@
 2019-07-26  Jonathan Wakely  <jwakely@redhat.com>
 
 	Backport from mainline
+	2019-07-16  Jason Merrill  <jason@redhat.com>
+
+	* include/std/memory (uses_allocator_construction_args): Add parens
+	around constraint.
+
+2019-07-26  Jonathan Wakely  <jwakely@redhat.com>
+
+	Backport from mainline
 	2019-07-02  Jonathan Wakely  <jwakely@redhat.com>
 
 	* include/bits/c++config (_GLIBCXX_HAVE_BUILTIN_LAUNDER)
diff --git a/libstdc++-v3/include/std/memory b/libstdc++-v3/include/std/memory
index 81e9ea3..8614abe 100644
--- a/libstdc++-v3/include/std/memory
+++ b/libstdc++-v3/include/std/memory
@@ -231,7 +231,7 @@ get_pointer_safety() noexcept { return pointer_safety::relaxed; }
     uses_allocator_construction_args(const _Alloc& __a,
 				     _Args&&... __args) noexcept
 #if __cpp_concepts
-    requires ! _Std_pair<_Tp>
+    requires (! _Std_pair<_Tp>)
 #endif
     {
       return std::__uses_alloc_args<_Tp>(__a, std::forward<_Args>(__args)...);