C++ Forward_list Library - sort() Function

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Description

The C++ function std::forward_list::sort() sorts the elements of the forward_list. The order of equal elements is preserved. It uses comparison function to compare values.

Declaration

Following is the declaration for std::forward_list::sort() function form std::forward_list header.

C++11

template <class Compare>
void sort (Compare comp);

Parameters

comp − comparison function object which returns ​boolean. It has following prototype.

bool cmp(const Type1 &arg1, const Type2 &arg2);

Return value

None

Exceptions

This member function never throws exception.

Time complexity

Linear i.e. O(n)

Example

The following example shows the usage of std::forward_list::sort() function.

#include <iostream>
#include <forward_list>

using namespace std;

bool cmp_fun(int a, int b) {
   return a > b;
}

int main(void) {

   forward_list<int> fl = {1, 4, 2, 5, 3};

   cout << "List contents before sorting" << endl;
   for (auto it = fl.begin(); it != fl.end(); ++it)
      cout << *it << endl;

   fl.sort(cmp_fun);

   cout << "List contents after sorting" << endl;
   for (auto it = fl.begin(); it != fl.end(); ++it)
      cout << *it << endl;

   return 0;
}

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

List contents before sorting
1
4
2
5
3
List contents after sorting
5
4
3
2
1