cpp/ranges/enumerate view/iterator/operator arith

Increments or decrements the.

Let be the underlying iterator and  be the underlying index.

@1@ Equivalent to @2@ Equivalent to @3@ Equivalent to @4@ Equivalent to @5@ Equivalent to @6@ Equivalent to @7@ Equivalent to

Return value
@1,4,6,7@ @2@ (none) @3,5@ a copy of that was made before the change