On 5/19/19 5:44 PM, Marek Polacek wrote:
CWG 2094 partially reverts CWG 496, which means that volatile-qualified scalars
are, once again, trivially copyable; [basic.types] now says "Scalar types,
trivially copyable class types, arrays of such types, and cv-qualified
versions of these types are collectively called trivially copyable types."
This previously changed in c++/63959 and this patch pretty much just reverts it.
I'm CCing libstdc++ because a test in libstdc++ needed updating.
Links to aforementioned CWGs:
<http://wg21.link/cwg496>
<http://wg21.link/cwg2094>
Bootstrapped/regtested on x86_64-linux, ok for trunk? Not planning to backport
this.
2019-05-19 Marek Polacek <pola...@redhat.com>
CWG 2094 - volatile scalars are trivially copyable.
PR c++/85679
* tree.c (trivially_copyable_p): Don't check CP_TYPE_VOLATILE_P for
scalar types.
* g++.dg/ext/is_trivially_constructible1.C: Change the expected result
for volatile int.
* g++.dg/ext/is_trivially_copyable.C: New test.
* testsuite/20_util/is_trivially_copyable/value.cc: Change the expected
result for volatile int.
diff --git gcc/gcc/cp/tree.c gcc/gcc/cp/tree.c
index 8d7f7a2c3e7..821f2b79a67 100644
--- gcc/gcc/cp/tree.c
+++ gcc/gcc/cp/tree.c
@@ -4098,7 +4098,8 @@ trivially_copyable_p (const_tree t)
&& !TYPE_HAS_COMPLEX_MOVE_ASSIGN (t)
&& TYPE_HAS_TRIVIAL_DESTRUCTOR (t));
else
- return !CP_TYPE_VOLATILE_P (t) && scalarish_type_p (t);
+ /* CWG 2094 makes volatile-qualified scalars trivially copyable. */
I'd add "again".
OK, thanks.
Jason
