swap
Exchanges the values of the elements between two types of objects
Definition
The swap() algorithm is defined in the standard header <algorithm> and in the nonstandard backward-compatibility header <algo.h>.
Interface
#include <algorithm>
template <class Type>
void swap(
Type& left,
Type& right
);Parameters:
| Parameter | Description |
| left | The first object to have its elements exchanged |
| right | The second object to have its elements exchanged |
Description
Swap assigns the contents of left to right and the contents of right to left.
Return Value
None.
Complexity
Swap algorithm has a constant complexity. It performs one copy construction and two assignments.
Example 1
Problem
This program illustrates the functionality of swap algorithm.
Workings
#include <vector>
#include <algorithm>
#include <iostream>
using namespace std;
bool greaterthan(int value)
{ return value > 5;
}
int main()
{
vector <int> vec1, vec2;
vector <int>::iterator Iter1, Iter2, result;
int i;
for (i = 10; i<= 20; i++)
vec1.push_back(i);
int j;
for(j = 10; j <= 15; j++)
vec2.push_back(j);
cout<<"Vector vec1 data is:\n";
for(Iter1 = vec1.begin(); Iter1 != vec1.end(); Iter1++)
cout <<*Iter1<<" ";
cout <<endl;
cout <<"\nVector vec2 data is:\n";
for (Iter2 = vec2.begin(); Iter2 != vec2.end(); Iter2++)
cout<<*Iter2<<" ";
cout <<endl;
swap(vec1, vec2);
cout <<"\nNow, vector vec1 data is:\n";
for(Iter1 = vec1.begin(); Iter1 != vec1.end(); Iter1++)
cout <<*Iter1<<" ";
cout <<endl;
cout <<"\nThen, vector vec2 data is:\n";
for (Iter2 = vec2.begin(); Iter2 != vec2.end(); Iter2++)
cout <<*Iter2<<" ";
cout <<endl;
return 0;
}Solution
Output:
Vector vec1 data is:
10 11 12 13 14 15 16 17 18 19 20
Vector vec2 data is:
10 11 12 13 14 15
Now, vector vec1 data is:
10 11 12 13 14 15
Then, vector vec2 data is:
10 11 12 13 14 15 16 17 18 19 20
References