public member function
<deque>

std::deque::size

size_type size() const;
size_type size() const noexcept;
Return size
Returns the number of elements in the deque container.

Parameters

none

Return Value

The number of elements in the container.

Member type size_type is an unsigned integral type.

Example

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

int main ()
{
  std::deque<int> myints;
  std::cout << "0. size: " << myints.size() << '\n';

  for (int i=0; i<5; i++) myints.push_back(i);
  std::cout << "1. size: " << myints.size() << '\n';

  myints.insert (myints.begin(),5,100);
  std::cout << "2. size: " << myints.size() << '\n';

  myints.pop_back();
  std::cout << "3. size: " << myints.size() << '\n';

  return 0;
}


Output:
0. size: 0
1. size: 5
2. size: 10
3. size: 9

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

  • 997351548 2018-02-20
  • 903691547 2018-02-20
  • 9127171546 2018-02-20
  • 2234751545 2018-02-20
  • 1685381544 2018-02-20
  • 911091543 2018-02-20
  • 9281021542 2018-02-20
  • 632231541 2018-02-20
  • 9751491540 2018-02-20
  • 8333621539 2018-02-20
  • 995001538 2018-02-20
  • 6477441537 2018-02-20
  • 511981536 2018-02-19
  • 2072881535 2018-02-19
  • 6024461534 2018-02-19
  • 7594061533 2018-02-19
  • 9311341532 2018-02-19
  • 4928331531 2018-02-19
  • 38561530 2018-02-19
  • 7776611529 2018-02-19