std::vector<T,Allocator>::rend, std::vector<T,Allocator>::crend
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vector::rendvector::crend
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reverse_iterator rend();
(1)
(noexcept since C++11) (constexpr since C++20)
const_reverse_iterator rend() const;
(2)
(noexcept since C++11) (constexpr since C++20)
const_reverse_iterator crend() const noexcept;
(3)
(since C++11) (constexpr since C++20)
Returns a reverse iterator past the last element of the reversed *this. It corresponds to the element preceding the first element of the non-reversed *this.
This returned iterator only acts as a sentinel. It is not guaranteed to be dereferenceable.
Contents
[edit] Return value
Reverse iterator to the element following the last element.
[edit] Complexity
Constant.
Notes
libc++ backports crend() to C++98 mode.
[edit] Example
Run this code
#include <algorithm> #include <iostream> #include <numeric> #include <string> #include <vector> int main() { std::vector <int> nums{1, 2, 4, 8, 16}; std::vector <std::string > fruits{"orange", "apple", "raspberry"}; std::vector <char> empty; // Print vector. std::for_each (nums.rbegin(), nums.rend(), [](const int n) { std::cout << n << ' '; }); std::cout << '\n'; // Sums all integers in the vector nums (if any), printing only the result. std::cout << "Sum of nums: " << std::accumulate (nums.rbegin(), nums.rend(), 0) << '\n'; // Prints the first fruit in the vector fruits, checking if there is any. if (!fruits.empty()) std::cout << "First fruit: " << *fruits.rbegin() << '\n'; if (empty.rbegin() == empty.rend()) std::cout << "vector 'empty' is indeed empty.\n"; }
Output:
16 8 4 2 1 Sum of nums: 31 First fruit: raspberry vector 'empty' is indeed empty.