NAME¶

std::experimental::ranges::iterator_category - std::experimental::ranges::iterator_category

Synopsis¶

Defined in header <experimental/ranges/iterator>
template< class I > (1)
struct iterator_category { };
template< class T > (2)
struct iterator_category<T*>;
template< class T > (3)
struct iterator_category<const T> : iterator_category<T> { };
template <class T>

requires requires { typename T::iterator_category; } (4)

struct iterator_category<T>;

Computes the iterator category of the class I, if any. Users may specialize
iterator_category for a program-defined type.

1) Primary template is an empty struct.
2) Specialization for pointers. If T is an object type, provides a member type type
equal to ranges::random_access_iterator_tag. Otherwise, there is no member type.
3) Specialization for const-qualified types.
4) Specialization for types that define a public and accessible member type
iterator_category. If T::iterator_category is the same as or derived from one of
iterator category tags in namespace std, it is mapped to the corresponding tag in
the namespace ranges as described below. Otherwise, provides a member type type
equal to T::iterator_category.

* If T::iterator_category is the same as or derives from
std::random_access_iterator_tag, provides a member type type equal to
ranges::random_access_iterator_tag.
* Otherwise, if T::iterator_category is the same as or derives from
std::bidirectional_iterator_tag, provides a member type type equal to
ranges::bidirectional_iterator_tag.
* Otherwise, if T::iterator_category is the same as or derives from
std::forward_iterator_tag, provides a member type type equal to
ranges::forward_iterator_tag.
* Otherwise, if T::iterator_category is the same as or derives from
std::input_iterator_tag, provides a member type type equal to
ranges::input_iterator_tag.
* Otherwise, if T::iterator_category is the same as or derives from
std::output_iterator_tag, there is no member type.

Helper alias template

template< class T >
using iterator_category_t = typename (ranges TS)
ranges::iterator_category<T>::type;

Example¶

This section is incomplete
Reason: no example

See also¶

input_iterator_tag
output_iterator_tag
forward_iterator_tag empty class types used to indicate iterator categories
bidirectional_iterator_tag (class)
random_access_iterator_tag
contiguous_iterator_tag
(C++20)
input_iterator_tag
output_iterator_tag empty class types used to indicate iterator categories
forward_iterator_tag (class)
bidirectional_iterator_tag
random_access_iterator_tag
compatibility traits class that collects an iterator’s
iterator_traits associated types
(alias template)