feature/spaceship: Clause 22: Container Iterators

[miscco]

This implements spaceship for the container iterators

[CaseyCarter]

What about basic_string and basic_string_view? (span is also notably covered by the Standard requirement, but we certainly have <=> for its iterators with test coverage elsewhere.)

[miscco]

basic_string_view

Urgh char_traits and string literal overloads...

[CaseyCarter]

basic_string_view

Urgh char_traits and string literal overloads...

The iterator <=> doesn't care about these things. (And the range <=> is in another PR so not your problem.)

[miscco]

basic_string_view

Urgh char_traits and string literal overloads...

The iterator <=> doesn't care about these things. (And the range <=> is in another PR so not your problem.)

I just pushed a commit for that ;) I like it when you agree that others should do the hard work

[CaseyCarter]

I've made a small change to add TRANSITION, GH-1635 to the two commented-out lines that would/could/should cover that work.

[CaseyCarter]

Apply warning cleanup for tests.

[StephanTLavavej]

I've pushed the following changes:

• Fix _HAS_CXX comment typo.
• The _Deque_const_iterator spaceship shouldn't be constexpr.
• Mark vector and vector<bool> iterator spaceships as _CONSTEXPR20_CONTAINER.
• Fix _STL_VERIFY message for _String_view_iterator spaceship, which isn't equality.
• Skip _Tree_const_iterator operator!= for C++20.
• Implement spaceships for stdext::checked_array_iterator and stdext::unchecked_array_iterator.
• Skip _Reinterpret_move_iter operator!= for C++20. (This is an internal iterator used to make unordered_meow moves more efficient.)
• When testing queue, there's no need to test deque iterators again, as they were tested above.
• Activate, reorder, and comment "string iterators", "string_view iterators" tests.
• Test checked_array_iterator and unchecked_array_iterator.

[StephanTLavavej]

Thanks for implementing this Secret Bonus Round of spaceships! 🥇 🛸 😹