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std::ranges::end(3) C++ Standard Libary std::ranges::end(3) 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 */; ob- ject) } 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_bor- rowed_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 expres- sion is valid and its converted type models std::sentinel_for<ranges::itera- tor_t<T>>, where the meaning of end is established as if by performing argument-de- pendent 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 im- mediate 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 implemen- tations. 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 retroac- tively to previously published C++ standards. DR Applied to Behavior as published Correct behavior P2602R2 C++20 there's machinery to prohibit certain re- moved 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) http://cppreference.com 2024.06.10 std::ranges::end(3)
NAME | Synopsis | Notes | Example | Output: | See also
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