C++ Set Library - set() Function

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Description

The C++ constructor std::set::set() (Copy Constructor) constructs the set container with the copy of the contents of other container. If alloc is not provided, allocator is obtained by calling

Declaration

Following is the declaration for std::set::set() copy constructor from std::set header.

C++98

set (const set& x);

C++11

set (const set& x);
set (const set& x, const allocator_type& alloc);

C++14

set (const set& x);
set (const set& x, const allocator_type& alloc);

Parameters

• alloc − Input iterator to initial position.

• x − Another set container object of the same type.

Return value

Constructor never returns any value.

Exceptions

This member function has no effect in case any exception is thrown.

Time complexity

Linear in size of other; i.e. O(n)

Example

The following example shows the usage of std::set::set() copy constructor.

#include <iostream>
#include <set>

using namespace std;

int main(void) {
   //Default Constructor
   std::set<int> t_set;
   t_set.insert(5);
   t_set.insert(10);

   std::cout << "Size of set container t_set is : " << t_set.size();
  
   // Copy constructor
   std::set<int> t_set_new(t_set);
   std::cout << "\nSize of new set container t_set_new is : " << t_set_new.size();
   return 0;
}

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

Size of set container t_set is : 2
Size of new set container t_set_new is : 2