Recently, when investigating stuffs in the standard library affected by WG21-N4258, I found that this exception specification isn't really strengthened:

The standard requirement (in [list.overview]/2) is saying noexcept(allocator_traits<Allocator>::is_always_equal::value), which hasn't changed since the adoption of N4258.

Looking at the definition of _Choose_pocma_v, it can be inferred that _Choose_pocma_v<_Alnode> == _Pocma_values::_Equal_allocators and allocator_traits<_Alnode>::is_always_equal::value are actually equal.

It's not very clear whether we're allowed use this value, see LWG-3267. But it is clear that this is not strengthening!

I believe we should remove the misleading /* strengthened */ comment.

Moreover, the exception specification of the move assignment operators of deque and (unordered) associative containers are spelt differently and more close to the forms specified in the standard. So perhaps we should spell the one of list as noexcept(_Alnode_traits::is_always_equal::value).

There's another _Choose_pocma_v<_Alnode> == _Pocma_values::_Equal_allocators in <xtree>. I guess it would be more consistent to write _Alnode_traits::is_always_equal::value instead.

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