CA178 17.11.07 [cmp.alg] Special-case std::strong/weak/partial_order for pointers LWG 3324

[wg21bot]

std::strong_order, weak_order, and partial_order have special cases for floating point, but are missing special casing for pointers (whereas compare_three_way and std::less have the special casing for pointers)

Proposed change:

1. Change [cmp.alg] bullet 1.4 from
   "Otherwise, strong_ordering(E <=> F) if it is a well-formed expression."
   to
   "Otherwise, strong_ordering(compare_three_way()(E, F)) if it is a well-formed expression."

2. Change [cmp.alg] bullet 2.4 from
   "Otherwise, weak_ordering(E <=> F) if it
   is a well-formed expression."
   to
   "Otherwise, weak_ordering(compare_three_way()(E, F)) if it is a well-formed expression."

3. Change [cmp.alg] bullet 3.3 from
   "Otherwise, partial_ordering(E <=> F) if
   it is a well-formed expression."
   to
   "Otherwise, partial_ordering(compare_three_way()(E, F)) if it is a well-formed expression."

[tituswinters]

LEWG in Belfast: Approved, send to LWG.

[dietmarkuehl]

LWG small group looked at that on Wednesday morning: recommend we do that

[Dani-Hub]

The associated issue is LWG 3324

[mclow]

Resolved by LWG 3324, which in status "Voting" for Prague.

[jensmaurer]

Accepted.