From cppreference.com
Defined in header
Defined in header
inlinenamespace/* unspecified */{inlineconstexpr/* unspecified */crend=/* unspecified */;}(since C++20)
(customization point object)Call signature
template<classT>requires/* see below */constexpr/* see below */autocrend(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.
Let CT be
conststd::remove_reference_t<T>& if the argument is an lvalue (i.e. T is an lvalue reference type),
constT otherwise.
A call to ranges::crend is
to ranges::rend(static_cast<CT&&>(t)).
(until C++23)If the argument is an lvalue or ranges::enable_borrowed_range<std::remove_cv_t<T>> is true, then a call to ranges::crend is
to:
std::const_sentinel<decltype(U)>(U) for some expression U equivalent to ranges::rend(
(t)).
In all other cases, a call to ranges::crend is ill-formed, which can result in
when the call appears in the immediate context of a template instantiation.
(since C++23)If ranges::crend(e) is valid for an expression e, where decltype((e)) is T, then CT models
, 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
if it models
.(since C++23)
Customization point objects
The name ranges::crend denotes a customization point object, which is a const
of a
class type. See
for details.
Example
Run this code
#include<algorithm>#include<iostream>#include<iterator>#include<vector>intmain(){inta[]{4,6,-3,9,10};std::cout<<"Array backwards: ";namespaceranges=std::ranges;ranges::copy(ranges::rbegin(a),ranges::rend(a),std::ostream_iterator<int>(std::cout," "));std::cout<<'\n';std::cout<<"Vector backwards: ";std::vectorv{4,6,-3,9,10};ranges::copy(ranges::rbegin(v),ranges::rend(v),std::ostream_iterator<int>(std::cout," "));std::cout<<'\n';}Output:
Array backwards: 10 9 -3 6 4 Vector backwards: 10 9 -3 6 4 See also
(C++20)
returns a reverse end iterator to a range
(customization point object)
(C++14)
returns a reverse end iterator for a container or array
(function template)