Docs4dev
Docs
cpp / latest / ranges / iterator_t.html

std::ranges::iterator_t, std::ranges::const_iterator_t, std::ranges::sentinel_t, std::ranges::const_sentinel_t, std::ranges::range_size_t, std::ranges::range_difference_t, std::ranges::range_value_t, std::ranges::range_reference_t

Defined in header <ranges> 
template< class T >
using iterator_t = decltype(ranges::begin(std::declval<T&>()));
 (1) (since C++20) 
template< ranges::range R >
using const_iterator_t = decltype(ranges::cbegin(std::declval<R&>()));
 (2) (since C++23) 
template< ranges::range R >
using sentinel_t = decltype(ranges::end(std::declval<R&>()));
 (3) (since C++20) 
template< ranges::range R >
using const_sentinel_t = decltype(ranges::cend(std::declval<R&>()));
 (4) (since C++23) 
template< ranges::sized_range R >
using range_size_t = decltype(ranges::size(std::declval<R&>()));
 (5) (since C++20) 
template< ranges::range R >
using range_difference_t = std::iter_difference_t<ranges::iterator_t<R>>;
 (6) (since C++20) 
template< ranges::range R >
using range_value_t = std::iter_value_t<ranges::iterator_t<R>>;
 (7) (since C++20) 
template< ranges::range R >
using range_reference_t = std::iter_reference_t<ranges::iterator_t<R>>;
 (8) (since C++20) 
template< ranges::range R >
using range_const_reference_t = 
    std::iter_const_reference_t<ranges::iterator_t<R>>;
 (9) (since C++23) 
template< ranges::range R >
using range_rvalue_reference_t =
    std::iter_rvalue_reference_t<ranges::iterator_t<R>>;
 (10) (since C++20) 
template< ranges::range R >
using range_common_reference_t =
    std::iter_common_reference_t<ranges::iterator_t<R>>;
 (11) (since C++20)
1) Used to obtain the iterator type of the type T.
2) Used to obtain the constant iterator type of the range type R.
3) Used to obtain the sentinel type of the range type R.
4) Used to obtain the constant sentinel type of the range type R.
5) Used to obtain the size type of the sized_range type R.
6) Used to obtain the difference type of the iterator type of range type R.
7) Used to obtain the value type of the iterator type of range type R.
8) Used to obtain the reference type of the iterator type of range type R.
9) Used to obtain the constant reference type of the iterator type of range type R.
10) Used to obtain the rvalue reference type of the iterator type of range type R.
11) Used to obtain the common reference type of the iterator type of range type R.

Template parameters

T - a type that can be used in std::ranges::begin
R - a range type or a sized_range type

Notes

iterator_t can be applied to non-range types, e.g. arrays with unknown bound.

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 3860 C++20 range_common_reference_t was missing added
LWG 3946 C++23 const_iterator_t and const_sentinel_t were inconsistent
with the result of ranges::cbegin and ranges::cend respectively		 tweaked

See also

(C++20)(C++20)(C++23)(C++20)(C++20)(C++20)
computes the associated types of an iterator
(alias template)

© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
https://en.cppreference.com/w/cpp/ranges/iterator_t