NAME¶

std::span::rend,std::span::crend - std::span::rend,std::span::crend

Synopsis¶

constexpr reverse_iterator rend() const noexcept; (1) (since C++20)
constexpr const_reverse_iterator crend() const noexcept; (2) (since C++23)

Returns a reverse iterator to the element following the last element of the reversed
span. It corresponds to the element preceding the first element of the non-reversed
span. This element acts as a placeholder, attempting to access it results in
undefined behavior.

range-rbegin-rend.svg

Parameters¶

(none)

Return value¶

Reverse iterator to the element following the last element.

Complexity¶

Constant.

Example¶

// Run this code

#include <algorithm>
#include <iostream>
#include <span>
#include <string_view>

void ascending(const std::span<const std::string_view> data,
const std::string_view term)
{
std::for_each(data.begin(), data.end(),
[](const std::string_view x) { std::cout << x << ' '; });
std::cout << term;
}

void descending(const std::span<const std::string_view> data,
const std::string_view term)
{
std::for_each(data.rbegin(), data.rend(),
[](const std::string_view x) { std::cout << x << ' '; });
std::cout << term;
}

int main()
{
constexpr std::string_view bars[]{"▁","▂","▃","▄","▅","▆","▇","█"};
ascending(bars, " ");
descending(bars, "\n");
}

Output:¶

▁ ▂ ▃ ▄ ▅ ▆ ▇ █ █ ▇ ▆ ▅ ▄ ▃ ▂ ▁

See also¶

rbegin returns a reverse iterator to the beginning
crbegin (public member function)
(C++23)
rend returns a reverse end iterator for a container or array
crend (function template)
(C++14)