public member function
<deque>

std::deque::empty

bool empty() const;
bool empty() const noexcept;
Test whether container is empty
Returns whether the deque container is empty (i.e. whether its size is 0).

This function does not modify the container in any way. To clear the content of a deque container, see deque::clear.

Parameters

none

Return Value

true if the container size is 0, false otherwise.

Example

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// deque::empty
#include <iostream>
#include <deque>

int main ()
{
  std::deque<int> mydeque;
  int sum (0);

  for (int i=1;i<=10;i++) mydeque.push_back(i);

  while (!mydeque.empty())
  {
     sum += mydeque.front();
     mydeque.pop_front();
  }

  std::cout << "total: " << sum << '\n';

  return 0;
}

The example initializes the content of the container to a sequence of numbers (form 1 to 10). It then pops the elements one by one until the container is empty and calculates their sum.

Output:
total: 55

Complexity

Constant.

Iterator validity

No changes.

Data races

The container is accessed.
No contained elements are accessed: concurrently accessing or modifying them is safe.

Exception safety

No-throw guarantee: this member function never throws exceptions.

See also

  • 9316991614 2018-02-25
  • 191841613 2018-02-25
  • 16411612 2018-02-25
  • 6081981611 2018-02-25
  • 1784561610 2018-02-25
  • 4651609 2018-02-25
  • 9348111608 2018-02-25
  • 2513771607 2018-02-25
  • 6478461606 2018-02-24
  • 4985791605 2018-02-24
  • 5637141604 2018-02-24
  • 282181603 2018-02-24
  • 6217941602 2018-02-24
  • 5076141601 2018-02-24
  • 714281600 2018-02-24
  • 6607141599 2018-02-24
  • 949041598 2018-02-24
  • 6809961597 2018-02-24
  • 671871596 2018-02-24
  • 7107821595 2018-02-24