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Description

The C++ copy constructor std::stack::stack() constructs a stack with copy of each elements present in another stack.

Declaration

Following is the declaration for std::stack::stack() constructor form std::stack header.

C++11

template <class Alloc>
stack (const stack& x, const Alloc& alloc);

Parameters

• x − Another stack object of same type.

• alloc − Allocator object.

Return value

Constructor never returns value.

Exceptions

This member function never throws exception.

Time complexity

Linear i.e. O(n)

Example

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

#include <iostream>
#include <stack>

using namespace std;

int main(void) {   
   stack<int> s1;

   for (int i = 0; i < 5; ++i)
      s1.push(i + 1);

   stack<int> s2(s1);

   cout << "Contents of stack s2" << endl;
   while (!s2.empty()) {
      cout << s2.top() << endl;
      s2.pop();
   }

   return 0;
}

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

Contents of stack s2
5
4
3
2
1

stack.htm