23 General utilities library [utilities]

23.7 Variants [variant]

23.7.13 Allocator-related traits [variant.traits]

template <class... Types, class Alloc> struct uses_allocator<variant<Types...>, Alloc> : true_type { };
Requires: Alloc shall be an Allocator.
[Note
:
Specialization of this trait informs other library components that variant can be constructed with an allocator, even though it does not have a nested allocator_­type.
end note
]