User:Cooky/iterator/basic const iterator

is an iterator adaptor which behaves exactly like the underlying iterator (which must be at least an or model ), except that dereferencing converts the value returned by the underlying iterator as immutable. This iterator can never be used as an output iterator because modifying elements is not allowed.

Helper alias templates
If models cpp/ranges/constant_range (an exposition-only concept), then  denotes a type. Otherwise,.

If models, then  denotes a type. Otherwise,.