Is this right? What does it mean that the previous template parameter Compare is defaulted, but Allocator isn't, even though both corresponding function parameters are defaulted? Seems like you can't get this to work without defaulting this Allocator: https://godbolt.org/z/fYesrsbMz.

           class Allocator = allocator<ranges::range_value_t<R>>>

           class Allocator = allocator<@\exposid{range-mapped-type}@<R>>>

I think both suggestions fulfill the corresponding Constraints element.

           class Allocator = allocator<void>>

Originally posted by @JohelEGP in #5626 (comment)

See also https://github.com/cplusplus/draft/pull/5626/files#r922820452.