bidirectional-iterator-tag-struct.md

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Learn more about: bidirectional_iterator_tag Struct	bidirectional_iterator_tag Struct	11/04/2016	xutility/std::bidirectional_iterator_tag	bidirectional_iterator_tag class bidirectional_iterator_tag struct	9ac06066-b8ae-44b6-bee4-b05855f6a31a

bidirectional_iterator_tag Struct

A class that provides a return type for iterator_category function that represents a bidirectional iterator.

Syntax

struct bidirectional_iterator_tag    : public forward_iterator_tag {};

Remarks

The category tag classes are used as compile tags for algorithm selection. The template function needs to find the most specific category of its iterator argument, so that it can use the most efficient algorithm at compile time. For every iterator of type Iterator, iterator_traits< Iterator>:: iterator_category must be defined to be the most specific category tag that describes the iterator's behavior.

The type is the same as iterator< Iter>:: iterator_category when Iter describes an object that can serve as a bidirectional iterator.

Example

See random_access_iterator_tag for an example of how to use bidirectional_iterator_tag.

Requirements

Header: <iterator>

Namespace: std

See also

forward_iterator_tag Struct
Thread Safety in the C++ Standard Library
C++ Standard Library Reference