public member function

std::set::size

<set>
size_type size() const;
Return container size
Returns the number of elements in the container.

Parameters

none

Return Value

The number of elements that conform the set's content.

Member type size_type is an unsigned integral type.

Example

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// set::size
#include <iostream>
#include <set>
using namespace std;

int main ()
{
  set<int> myints;
  cout << "0. size: " << (int) myints.size() << endl;

  for (int i=0; i<10; i++) myints.insert(i);
  cout << "1. size: " << (int) myints.size() << endl;

  myints.insert (100);
  cout << "2. size: " << (int) myints.size() << endl;

  myints.erase(5);
  cout << "3. size: " << (int) myints.size() << endl;

  return 0;
}


Output:
0. size: 0
1. size: 10
2. size: 11
3. size: 10

Complexity

Constant.

See also

set::max_size
Return maximum size (public member function)
set::empty
Test whether container is empty (public member function)