[Bug c++/50248] [C++0x] unnecessary instantiation of constexpr constructor

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50248

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2011-08-31
         AssignedTo|unassigned at gcc dot       |jason at gcc dot gnu.org
                   |gnu.org                     |
            Summary|[C++0x] tries to use        |[C++0x] unnecessary
                   |variadic constructor when   |instantiation of constexpr
                   |it should use default       |constructor
                   |constructor                 |
     Ever Confirmed|0                           |1

--- Comment #2 from Jason Merrill <jason at gcc dot gnu.org> 2011-08-31 13:29:33 UTC ---
The copy constructor isn't being defined, but the compiler is instantiating the
constexpr constructor to find out if it is really constexpr, and therefore
whether the implicitly-declared copy constructor should be declared constexpr.

We decided at Bloomington that we should just consider instantiations of
constexpr templates to be constexpr, not instantiate them to check.