How to use the set::size STL function in Visual C++

MORE INFORMATION

Required Header

   <set>
				

Prototype

   template<class _K, class _Pr, class _A>
   class set {
   public:
   // Function 1:

      size_type size() const;

   }
				

NOTE: The class/parameter names in the prototype may not match the version in the header file. Some have been modified to improve readability.

Description

The size function is used to determine the number of elements in the controlled sequence.

Sample Code

////////////////////////////////////////////////////////////////////// 
// 
// Compile options needed: -GX
// 
// SetSize.cpp:
//      Illustrates how to use the size function to determine how
//      many elements are in the controlled sequence.
// 
// Functions:
// 
//    size         Returns the number of elements in the controlled
//                 sequence.
// 
// Written by Derek Jamison
// of Microsoft Technical Support,
// Copyright (c) 1996 Microsoft Corporation. All rights reserved.
////////////////////////////////////////////////////////////////////// 

#pragma warning(disable:4786)

#include <set>
#include <iostream>

#if _MSC_VER > 1020   // if VC++ version is > 4.2
   using namespace std;  // std c++ libs implemented in std
   #endif

typedef set<int,less<int>,allocator<int> > SET_INT;

void main() {

  SET_INT s1;

  cout << "s1.size() returned ";
  cout << s1.size() << endl;  // 0

  cout << "s1.insert(5)" << endl;
  s1.insert(5);
  cout << "s1.insert(8)" << endl;
  s1.insert(8);
  cout << "s1.insert(12)" << endl;
  s1.insert(12);

  cout << "s1.size() returned ";
  cout << s1.size() << endl; // 3
}
				

Program Output

s1.size() returned 0
s1.insert(5)
s1.insert(8)
s1.insert(12)
s1.size() returned 3