Namespaces
Variants
Views
Actions

std::incrementable

From cppreference.com
< cpp‎ | iterator
 
 
Iterator library
Iterator concepts
Iterator primitives
Algorithm concepts and utilities
Indirect callable concepts
Common algorithm requirements
(C++20)
(C++20)
(C++20)
Utilities
(C++20)

Iterator adaptors
Iterator customization points
Iterator operations
(C++11)    
(C++11)
Range access
(C++11)(C++14)
(C++14)(C++14)    
(C++11)(C++14)
(C++14)(C++14)    
(C++17)(C++20)
(C++17)
(C++17)
 
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.

[edit] 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).

[edit] Equality preservation

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

[edit] See also

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