22 Iterators library [iterators]

22.5 Iterator adaptors [predef.iterators]

22.5.4 Common iterators [iterators.common]

22.5.4.5 Navigation [common.iter.nav]

common_iterator& operator++();
Expects: holds_­alternative<I>(v_­).
Effects: Equivalent to ++get<I>(v_­).
Returns: *this.
decltype(auto) operator++(int);
Expects: holds_­alternative<I>(v_­).
Effects: If I models ForwardIterator, equivalent to:
common_iterator tmp = *this;
++*this;
return tmp;
Otherwise, equivalent to: return get<I>(v_­)++;