std::forward_list<T,Allocator>::begin, std::forward_list<T,Allocator>::cbegin
From cppreference.com
< cpp | container | forward list
| iterator begin() noexcept; |
(since C++11) | |
| const_iterator begin() const noexcept; |
(since C++11) | |
| const_iterator cbegin() const noexcept; |
(since C++11) | |
Returns an iterator to the first element of the container.
If the container is empty, the returned iterator will be equal to end().
Parameters
(none)
Return value
Iterator to the first element
Complexity
Constant
Example
Run this code
#include <iostream> #include <forward_list> #include <string> int main() { std::forward_list<int> ints {1, 2, 4, 8, 16}; std::forward_list<std::string> fruits {"orange", "apple", "raspberry"}; std::forward_list<char> empty; // Sums all integers in the forward_list ints (if any), printing only the result. int sum = 0; for (auto it = ints.cbegin(); it != ints.cend(); it++) sum += *it; std::cout << "Sum of ints: " << sum << "\n"; // Prints the first fruit in the forward_list fruits, without checking if there is one. std::cout << "First fruit: " << *fruits.begin() << "\n"; if (empty.begin() == empty.end()) std::cout << "forward_list 'empty' is indeed empty.\n"; }
Output:
Sum of ints: 31 First fruit: orange forward_list 'empty' is indeed empty.
See also
| returns an iterator to the end (public member function) |