[Bug libstdc++/78939] [C++17] <tuple> interferes with structured binding from struct

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78939

--- Comment #15 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Author: redi
Date: Fri May 12 15:53:19 2017
New Revision: 247978

URL: https://gcc.gnu.org/viewcvs?rev=247978&root=gcc&view=rev
Log:
PR libstdc++/78939 make tuple_size<cv T> depend on tuple_size<T>

        PR libstdc++/78939
        * include/std/utility (tuple_size<cv T>) [__cplusplus > 201402L]:
        Only define partial specializations when tuple_size<T>::value is
        valid.
        * testsuite/20_util/tuple/78939.cc: New.

Added:
    branches/gcc-7-branch/libstdc++-v3/testsuite/20_util/tuple/78939.cc
Modified:
    branches/gcc-7-branch/libstdc++-v3/ChangeLog
    branches/gcc-7-branch/libstdc++-v3/include/std/utility