C++ Unordered_set Library - operator=

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Description

It assigns ust as the new content for the container.

Declaration

Following is the declaration for std::unordered_set::operator=.

C++11

unordered_set& operator= ( const unordered_set& ust );

Parameters

• ust − It is an another unordered_set object of the same type.

• il − It is an initializer_list object.

Return value

It returns *this.

Exceptions

Exception is thrown if any element comparison object throws exception.

Please note that invalid arguments cause undefined behavior.

Time complexity

Linear in sizes.

Example

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

#include <iostream>
#include <string>
#include <unordered_set>

template<class T>
T cmerge (T a, T b) {
   T t(a); t.insert(b.begin(),b.end()); return t;
}

int main () {
   std::unordered_set<std::string> first, second, third;
   first = {"100","200","300"};      
   second = {"400","500","600"}; 
   third = cmerge (first, second);
   first = third;                 

   std::cout << "first contains:";
   for (const std::string& x: first) std::cout << " " << x;
   std::cout << std::endl;

   return 0;
}

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

first contains: 400 600 200 500 300 100