std::ranges::cend

Returns a sentinelfor the constant iterator(since C++23) indicating the end of a const-qualified(until C++23)

If ranges::cend(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::cend(e)) , and I is decltype( ranges::cbegin (e) ) . Additionally, S models constant-iterator if it models input_iterator (since C++23)

Customization point objects

The name ranges::cend denotes a customization point object, which is a const function object of a literal semiregular class type. For exposition purposes, the cv-unqualified version of its type is denoted as __cend_fn

All instances of __cend_fn are equal. The effects of invoking different instances of type __cend_fn on the same arguments are equivalent, regardless of whether the expression denoting the instance is an lvalue or rvalue, and is const-qualified or not (however, a volatile-qualified instance is not required to be invocable). Thus, ranges::cend

Given a set of types Args..., if std::declval <Args> ( ) meet the requirements for arguments to ranges::cend above, __cend_fn models

• std::invocable<__cend_fn, Args...>
• std::invocable < const __cend_fn, Args...>
• std::invocable <__cend_fn&, Args...>
• std::invocable < const __cend_fn&, Args...> .
  

Otherwise, no function call operator of __cend_fn participates in overload resolution.

Example

#include <algorithm>
#include <cassert>
#include <ranges>
#include <vector>
 
int main()
{
    std::vector vec{3, 1, 4};
    int arr[]{5, 10, 15};
 
    assert(std::ranges::find(vec, 5) == std::ranges::cend(vec));
    assert(std::ranges::find(arr, 5) != std::ranges::cend(arr));
}

See also