[v3 PATCH] Support allocators in tuples of zero size.

[Jonathan Wakely]

On 05/06/16 21:15 +0300, Ville Voutilainen wrote:
>     {
>     public:
>       void swap(tuple&) noexcept { /* no-op */ }
>+      // We need the default since we're going to define no-op
>+      // allocator constructors.
>+      tuple() = default;
>+      // No-op allocator constructors.
>+      template<typename _Alloc>
>+	tuple(allocator_arg_t __tag, const _Alloc& __a) { }
>+      template<typename _Alloc>
>+	tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple& __in) { }

Please remove the names of the unused parameters, so we don't get
warnings with -Wsystem-headers -Wunused-parameter.

OK with that change, thanks.