next_permutation

Hi guys,

I've never used this function before, and have a need for it today. I'm getting a lovely bunch of compiler errors...I swear I'm sending in the iterators that it wants.

This program is simply a test for me to figure out this function, and make sure I can use it with vectors. I can handle it with simply arrays of simply data types, but things are a little harry now. Any advice?

Code:

---

#include<iostream>
#include<algorithm>
#include<vector>
#include"computer.h"

using namespace std;

int main()
{
    vector<Computer> computers;
    Computer comp;
    for (int i = 0; i < 4; i++)
    {
        comp.setLetter(i + 97);
        computers.push_back(comp);
    }
    while (next_permutation(computers.begin(), computers.end())) // Problems here?
    {
        for (int i = 0; i < 4; i++)
        {
            cout << computers[i].getLetter();
        }
        cout << endl;
    }
    return 0;
}

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Yeah, I figured it out...had to overload my < operator. Dumb me...

Carry on!

You could also have used a predicate function object to make the comparison.

Code:

---

bool CompareComputer(Computer left, Computer right)
{
  //...
  return true/false;
}

//...

next_permutation(computers.begin(), computers.end(), CompareComputer)

---

Yeah, I just wasn't thinking...I've used both methods before in other parts of the stl (priority queues, etc.)