std::ranges::ends_with

Since C++23

Header: <algorithm>

Checks whether the second range matches the suffix of the first range.

# Declarations

Call signature

template< std::input_iterator I1, std::sentinel_for<I1> S1,
std::input_iterator I2, std::sentinel_for<I2> S2,
class Pred = ranges::equal_to,
class Proj1 = std::identity, class Proj2 = std::identity >
requires (std::forward_iterator<I1> || std::sized_sentinel_for<S1, I1>) &&
(std::forward_iterator<I2> || std::sized_sentinel_for<S2, I2>) &&
std::indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
constexpr bool ends_with( I1 first1, S1 last1,
I2 first2, S2 last2, Pred pred = {},
Proj1 proj1 = {}, Proj2 proj2 = {} );

(since C++23)

template< ranges::input_range R1, ranges::input_range R2,
class Pred = ranges::equal_to,
class Proj1 = std::identity, class Proj2 = std::identity >
requires (ranges::forward_range<R1> || ranges::sized_range<R1>) &&
(ranges::forward_range<R2> || ranges::sized_range<R2>) &&
std::indirectly_comparable<ranges::iterator_t<R1>,
ranges::iterator_t<R2>,
Pred, Proj1, Proj2>
constexpr bool ends_with( R1&& r1, R2&& r2, Pred pred = {},
Proj1 proj1 = {}, Proj2 proj2 = {} );

(since C++23)

# Parameters

first1, last1: the range of elements to examine
r1: the range of elements to examine
first2, last2: the range of elements to be used as the suffix
r2: the range of elements to be used as the suffix
pred: the binary predicate that compares the projected elements
proj1: the projection to apply to the elements of the range to examine
proj2: the projection to apply to the elements of the range to be used as the suffix

# Return value

true if the second range matches the suffix of the first range, false otherwise.

# Notes

Feature-test macro Value Std Feature __cpp_lib_ranges_starts_ends_with 202106L (C++23) std::ranges::starts_with, std::ranges::ends_with

# Example

#include <algorithm>
#include <array>
 
static_assert
(
    ! std::ranges::ends_with("for", "cast") &&
    std::ranges::ends_with("dynamic_cast", "cast") &&
    ! std::ranges::ends_with("as_const", "cast") &&
    std::ranges::ends_with("bit_cast", "cast") &&
    ! std::ranges::ends_with("to_underlying", "cast") &&
    std::ranges::ends_with(std::array{1, 2, 3, 4}, std::array{3, 4}) &&
    ! std::ranges::ends_with(std::array{1, 2, 3, 4}, std::array{4, 5})
);
 
int main() {}

# Defect reports

DR	Applied to	Behavior as published	Correct behavior
LWG 4105	C++23	overload (2) calculated the sizedifference by N1 - N2[1]	changed toN1 - static_cast<decltype(N1)>(N2)