C++ Map Library - operator== Function


Advertisements


Description

The C++ function std::multimap::operator== tests whether two mutlimaps are equal or not.

Declaration

Following is the declaration for std::multimap::operator== function form std::map header.

C++98

template <class Key, class T, class Compare, class Alloc>
bool operator== ( const multimap<Key,T,Compare,Alloc>& m1,
                  const multimap<Key,T,Compare,Alloc>& m2);

Parameters

  • m1 − First multimap object.

  • m2 − Second multimap object.

Return value

Returns true if both mutlimap are equal otherwise false.

Exceptions

No effect on container if exception is thrown.

Time complexity

Linear i.e. O(n)

Example

The following example shows the usage of std::multimap::operator== function.

Live Demo
#include <iostream>
#include <map>

using namespace std;

int main(void) {
   /* Multimap with duplicates */
   multimap<char, int> m1;
   multimap<char, int> m2;

   if (m1 == m2)
      cout << "Both multimaps are equal." << endl;

   m1.insert(pair<char, int>('a', 1));

   if (!(m1 == m2))
      cout << "Both multimaps are not equal." << endl;

   return 0;
}

Let us compile and run the above program, this will produce the following result −

Both multimaps are equal.
Both multimaps are not equal.

map.htm

Advertisements