public member function
<deque>

std::deque::cbegin

const_iterator cbegin() const noexcept;
Return const_iterator to beginning
Returns a const_iterator pointing to the first element in the container.

A const_iterator is an iterator that points to const content. This iterator can be increased and decreased (unless it is itself also const), just like the iterator returned by deque::begin, but it cannot be used to modify the contents it points to, even if the deque object is not itself const.

If the container is empty, the returned iterator value shall not be dereferenced.

Parameters

none

Return Value

A const_iterator to the beginning of the sequence.

Member type const_iterator is a random access iterator type that points to a const element.

Example

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// deque::cbegin/cend
#include <iostream>
#include <deque>

int main ()
{
  std::deque<int> mydeque = {10,20,30,40,50};

  std::cout << "mydeque contains:";

  for (auto it = mydeque.cbegin(); it != mydeque.cend(); ++it)
    std::cout << ' ' << *it;

  std::cout << '\n';

  return 0;
}


Output:
mydeque contains: 10 20 30 40 50

Complexity

Constant.

Iterator validity

No changes.

Data races

The container is accessed.
No contained elements are accessed by the call, but the iterator returned can be used to access them. Concurrently accessing or modifying different elements is safe.

Exception safety

No-throw guarantee: this member function never throws exceptions.
The copy construction or assignment of the returned iterator is also guaranteed to never throw.

See also

deque::begin
Return iterator to beginning (public member function )
deque::cend
Return const_iterator to end (public member function )
deque::crbegin
Return const_reverse_iterator to reverse beginning (public member function )

C++