https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63924
Jason Merrill <jason at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |ASSIGNED
Last reconfirmed| |2014-11-19
CC| |jason at gcc dot gnu.org
Assignee|unassigned at gcc dot gnu.org |jason at gcc dot gnu.org
Target Milestone|--- |5.0
Ever confirmed|0 |1
--- Comment #2 from Jason Merrill <jason at gcc dot gnu.org> ---
> constexpr auto size3 (test t) { return require_constexpr< size0(t) >::value; }
The problem here is that 't' is non-constant within size3 and the implicit
trivial copy constructor does a bitwise copy, which involves copying a
(non-constant) byte of padding, whereas your user-provided copy constructor
doesn't copy anything. This seems like a grey area in the standard, but I'll
go ahead and make it work for now.
