std:: incrementable

Defined in header <iterator>
template < class I > concept incrementable = std:: regular < I > && std:: weakly_incrementable < I > && requires ( I i ) { { i ++ } - > std:: same_as < I > ; } ;		(since C++20)

This concept specifies requirements on types that can be incremented with the pre- and post-increment operators, whose increment operations are equality-preserving , and the type is std::equality_comparable .

Unlike with std::weakly_incrementable , which only support single-pass algorithms, multi-pass one-directional algorithms can be used with types that model std::incrementable .

Semantic requirements

I models std::incrementable only if given any two incrementable objects a and b of type I :

• bool ( a == b ) implies bool ( a ++ == b ) , and
• bool ( a == b ) implies bool ( ( ( void ) a ++ , a ) == ++ b ) .

Equality preservation

Expressions declared in requires expressions of the standard library concepts are required to be equality-preserving (except where stated otherwise).

See also

weakly_incrementable (C++20)	specifies that a semiregular type can be incremented with pre- and post-increment operators (concept)
same_as (C++20)	specifies that a type is the same as another type (concept)