std::ranges::crend
Defined in header <ranges> | ||
|---|---|---|
Defined in header <iterator> | ||
inline namespace /* unspecified */ {
inline constexpr /* unspecified */ crend = /* unspecified */;
}
| (since C++20) (customization point object) | |
| Call signature | ||
template< class T >
requires /* see below */
constexpr /* see below */ auto crend( T&& t );
| (since C++20) |
Returns a sentinel for the constant iterator(since C++23) indicating the end of a const-qualified(until C++23) range that is treated as a reversed sequence.
| Let
A call to | (until C++23) |
| If the argument is an lvalue or
In all other cases, a call to | (since C++23) |
If ranges::crend(e) is valid for an expression e, where decltype((e)) is T, then CT models std::ranges::range, and(until C++23) std::sentinel_for<S, I> is true in all cases, where S is decltype(ranges::crend(e)), and I is decltype(ranges::crbegin(e)). Additionally, S models constant-iterator if it models input_iterator.(since C++23)
Customization point objects
The name ranges::crend denotes a customization point object, which is a const function object of a literal semiregular class type. See CustomizationPointObject for details.
Example
#include <algorithm>
#include <iostream>
#include <iterator>
#include <vector>
int main()
{
int a[]{4, 6, -3, 9, 10};
std::cout << "Array backwards: ";
namespace ranges = std::ranges;
ranges::copy(ranges::rbegin(a), ranges::rend(a),
std::ostream_iterator<int>(std::cout, " "));
std::cout << '\n';
std::cout << "Vector backwards: ";
std::vector v{4, 6, -3, 9, 10};
ranges::copy(ranges::rbegin(v), ranges::rend(v),
std::ostream_iterator<int>(std::cout, " "));
std::cout << '\n';
}
Output:
Array backwards: 10 9 -3 6 4 Vector backwards: 10 9 -3 6 4
See also
|
(C++20) | returns a reverse end iterator to a range (customization point object) |
|
(C++14) | returns a reverse end iterator for a container or array (function template) |
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https://en.cppreference.com/cpp/ranges/crend
