[v3 PATCH] Make the perfect-forwarding constructor of a two-element tuple sfinae away when the first argument is an allocator_arg.

[Jonathan Wakely]

On 18/12/16 13:33 +0200, Ville Voutilainen wrote:
>Andrzej Krzemienski pointed this out in a discussion related to any and tags.
>Our two-element tuple specialization doesn't make the perfect-forwarding
>constructor and the allocator constructor properly mutually exclusive; this
>patch fixes that.
>
>Tested on Linux-x64, ok for trunk, gcc-6 and gcc-5?

gcc-6-branch is frozen, so not there.

OK for trunk and gcc-5-branch.

Should this be reported as a defect in the standard?