std::ranges::crend - cppreference.com (original) (raw)

| Defined in header | | | | ----------------------------------------------------------------------------------------------------------- | | ------------------------------------------ | | Defined in header | | | | inline namespace /* unspecified */ { inline constexpr /* unspecified */ crend = /* unspecified */; } | | (since C++20) (customization point object) | | Call signature | | | | template< class T > requires /* see below */ constexpr /* see below */ auto crend( T&& t ); | | (since C++20) |

Returns a sentinel for the constant iterator(since C++23) indicating the end of a const-qualified(until C++23) range that is treated as a reversed sequence.

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

Customization point objects

The name ranges::crend denotes a customization point object, which is a const function object of a literal semiregular class type. See CustomizationPointObject for details.

[edit] Example

#include #include #include #include   int main() { int a[]{4, 6, -3, 9, 10}; std::cout << "Array backwards: "; namespace ranges = std::ranges; ranges::copy(ranges::rbegin(a), ranges::rend(a), std::ostream_iterator(std::cout, " ")); std::cout << '\n';   std::cout << "Vector backwards: "; std::vector v{4, 6, -3, 9, 10}; ranges::copy(ranges::rbegin(v), ranges::rend(v), std::ostream_iterator(std::cout, " ")); std::cout << '\n'; }

Output:

Array backwards: 10 9 -3 6 4 Vector backwards: 10 9 -3 6 4

[edit] See also

| | returns a reverse end iterator to a range(customization point object)[edit] | | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | returns a reverse end iterator for a container or array (function template) [edit] |