NAME¶

std::ranges::end - std::ranges::end

Synopsis¶

Defined in header <ranges>
Defined in header <iterator>
inline namespace /* unspecified */ {
(since C++20)
inline constexpr /* unspecified */ end = /* unspecified (customization point
*/; object)

}
Call signature
template< class T >

requires /* see below */ (since C++20)

constexpr std::sentinel_for<ranges::iterator_t<T>> auto end(
T&& t );

Returns a sentinel indicating the end of a range.

range-begin-end.svg

If the argument is an lvalue or ranges::enable_borrowed_range<std::remove_cv_t<T>>
is true, then a call to ranges::end is expression-equivalent to:

1. t + std::extent_v<T> if t has an array type of known bound.
* If std::remove_all_extents_t<std::remove_reference_t<T>> is incomplete,
then the call to ranges::end is ill-formed, no diagnostic required.
2. Otherwise,
decay-copy(t.end())
(until C++23)
auto(t.end())
(since C++23), if that expression is valid, and its type models
std::sentinel_for<ranges::iterator_t<T>>.
3. Otherwise,
decay-copy(end(t))
(until C++23)
auto(end(t))
(since C++23), if T is a class or enumeration type, that expression is valid and
its converted type models std::sentinel_for<ranges::iterator_t<T>>, where the
meaning of end is established as if by performing argument-dependent lookup
only.

In all other cases, a call to ranges::end is ill-formed, which can result in
substitution failure when the call to ranges::end appears in the immediate context
of a template instantiation.

Notes¶

If the argument is an rvalue (i.e. T is an object type) and
ranges::enable_borrowed_range<std::remove_cv_t<T>> is false, or if it is of an array
type of unknown bound, the call to ranges::end is ill-formed, which also results in
substitution failure.

If ranges::end(std::forward<T>(t)) is valid, then
decltype(ranges::end(std::forward<T>(t))) and
decltype(ranges::begin(std::forward<T>(t))) model std::sentinel_for in all cases,
while T models std::ranges::range.

The C++20 standard requires that if the underlying end function call returns a
prvalue, the return value is move-constructed from the materialized temporary
object. All implementations directly return the prvalue instead. The requirement is
corrected by the post-C++20 proposal P0849R8 to match the implementations.

Example¶

// Run this code

#include <algorithm>
#include <iostream>
#include <ranges>
#include <vector>

int main()
{
std::vector<int> vec{3, 1, 4};
if (std::ranges::find(vec, 5) != std::ranges::end(vec))
std::cout << "found a 5 in vector vec!\n";

int arr[]{5, 10, 15};
if (std::ranges::find(arr, 5) != std::ranges::end(arr))
std::cout << "found a 5 in array arr!\n";
}

Output:¶

found a 5 in array arr!

Defect reports

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

DR Applied to Behavior as published Correct behavior
P2602R2 C++20 there's machinery to prohibit certain removed such machinery
non-member end found by ADL

See also¶

ranges::cend returns a sentinel indicating the end of a read-only range
(C++20) (customization point object)
ranges::begin returns an iterator to the beginning of a range
(C++20) (customization point object)
end
cend returns an iterator to the end of a container or array
(C++11) (function template)
(C++14)