[v3 PATCH] Implement P0513R0, Poisoning the Hash.

[Jonathan Wakely]

On 14/11/16 00:55 +0200, Ville Voutilainen wrote:
>    Implement P0513R0, Poisoning the Hash.
>    * include/bits/functional_hash.h (__poison_hash): New.
>    * include/bits/unique_ptr.h
>    (hash<unique_ptr<_Tp, _Dp>>): Derive from __poison_hash.
>    * include/std/optional (hash<optional<_Tp>>): Likewise.
>    * include/std/variant (hash<variant<_Types...>>): Likewise.
>    * testsuite/20_util/optional/hash.cc: New.
>    * testsuite/20_util/unique_ptr/assign/48635_neg.cc: Adjust.
>    * testsuite/20_util/unique_ptr/cons/cv_qual_neg.cc: Adjust.
>    * testsuite/20_util/unique_ptr/hash/1.cc: Add tests for
>    poisoned fancy pointer hashes.
>    * testsuite/20_util/variant/hash.cc: New.

OK, thanks.