On Mon, Sep 19, 2016 at 5:34 AM, Jonathan Wakely <jwak...@redhat.com> wrote: > As noted in bugzilla PR 77641 I don't think is_literal_type is the > right condition for _Uninitialized, because a type can have a > non-trivial default constructor but still be literal, but that means > it can't be used in the union in _Variant_storage. > > I'm not sure if the right condition is is_literal && > is_trivially_default_constructible, or if this is enough:
I believe that it's a "typo" from me - it should be is_trivially_destructible, not is_default_constructible (so that we can avoid using aligned_storage in the corresponding specialization). is_literal_type works, since literal types are trivially destructible. > > PR libstdc++/77641 > * include/std/variant (__detail::__variant::_Uninitialized): Check > is_trivially_default_constructible_v instead of is_literal_type_v. > * testsuite/20_util/variant/compile.cc: Test literal type with > non-trivial default constructor. > > Tim, are there case that this doesn't handle, where we need is_literal > as well? (bear in mind that is_trivially_default_constructible also > depends on trivially destructible). I checked for is_default_constructible, and all other sites are appropriate. -- Regards, Tim Shen
