[v3 PATCH] PR libstdc++/77802

[Jonathan Wakely]

On 01/10/16 00:12 +0300, Ville Voutilainen wrote:
>I do this with a rather heavy heart, but since gcc6 compiles boost 1.62,
>I'll rather have gcc7 do so as well, and I'll throw the tuple fix for lwg2729
>to the wolves not because I want to, but because I have to.
>
>Tested on Linux-x64.
>
>2016-10-01  Ville Voutilainen  <ville.voutilainen@gmail.com>
>
>    PR libstdc++/77802
>
>    * testsuite/20_util/tuple/77802.cc: New.

Could you please add a note to this new test saying it's undefined
behaviour to instantiate std::tuple with an incomplete type (but that
we try to support it anyway).

OK with that change.