Defined in header <iterator> | ||
|---|---|---|
template< class T > concept /*dereferenceable*/ = /* see below */; // exposition only | ||
template< class T > using iter_value_t = /* see below */; | (1) | (since C++20) |
template< /*dereferenceable*/ T > using iter_reference_t = decltype(*std::declval<T&>()); | (2) | (since C++20) |
template< std::indirectly_readable T >
using iter_const_reference_t = std::common_reference_t<const std::iter_value_t<T>&&,
std::iter_reference_t<T>>;
| (3) | (since C++23) |
template< class T > using iter_difference_t = /* see below */; | (4) | (since C++20) |
template< /*dereferenceable*/ T>
requires /* see below */
using iter_rvalue_reference_t = decltype(ranges::iter_move(std::declval<T&>()));
| (5) | (since C++20) |
template< std::indirectly_readable T >
using iter_common_reference_t = std::common_reference_t<std::iter_reference_t<T>,
std::iter_value_t<T>&>;
| (6) | (since C++20) |
Compute the associated types of an iterator. The exposition-only concept dereferenceable is satisfied if and only if the expression *std::declval<T&>() is valid and has a referenceable type (in particular, not void).
T. If std::iterator_traits<std::remove_cvref_t<T>> is not specialized, then std::iter_value_t<T> is std::indirectly_readable_traits<std::remove_cvref_t<T>>::value_type. Otherwise, it is std::iterator_traits<std::remove_cvref_t<T>>::value_type.T.T.T. If std::iterator_traits<std::remove_cvref_t<T>> is not specialized, then std::iter_difference_t<T> is std::incrementable_traits<std::remove_cvref_t<T>>::difference_type. Otherwise, it is std::iterator_traits<std::remove_cvref_t<T>>::difference_type.T. The "see below" portion of the constraint on this alias template is satisfied if and only if the expression ranges::iter_move(std::declval<T&>()) is valid and has a referenceable type (in particular, not void).T. This is the common reference type between its reference type and an lvalue reference to its value type.|
(C++20) | specifies that a type is indirectly readable by applying operator * (concept) |
|
(C++20) | specifies that a semiregular type can be incremented with pre- and post-increment operators (concept) |
|
(C++20) | computes the value type of an indirectly_readable type (class template) |
|
(C++20) | computes the difference type of a weakly_incrementable type (class template) |
| provides uniform interface to the properties of an iterator (class template) |
© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
https://en.cppreference.com/w/cpp/iterator/iter_t