std::deque<T,Allocator>::begin, std::deque<T,Allocator>::cbegin

< cpp‎ | container‎ | deque

iterator begin();
(until C++11)
iterator begin() noexcept;
(since C++11)
const_iterator begin() const;
(until 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().




Return value

Iterator to the first element




#include <iostream>
#include <deque>
#include <string>
int main()
	std::deque<int> ints {1, 2, 4, 8, 16};
	std::deque<std::string> fruits {"orange", "apple", "raspberry"};
	std::deque<char> empty;
	// Sums all integers in the deque 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 deque fruits, without checking if there is one.
	std::cout << "First fruit: " << *fruits.begin() << "\n";
	if (empty.begin() == empty.end())
		std::cout << "deque 'empty' is indeed empty.\n";


Sum of ints: 31
First fruit: orange
deque 'empty' is indeed empty.

See also

returns an iterator to the end
(public member function)