Thread: Overloading the < Operator

I've been trying to overload the operator, so I can use a class for a priority_queue, thus far i have:

Code:

In function `bool operator<(const Thread&, const Thread&)':
71: passing `const Thread' as `this' argument of `int Thread::getreq()'
   discards qualifiers
71: passing `const Thread' as `this' argument of `int Thread::getreq()'
   discards qualifiers

and my attempt at overloading is:

Code:

bool operator<(const Thread &a, const Thread &b)
{
   bool result = a.getreq() < b.getreq();
   return result;
}

Now, checking out the other threads on here, there were one or two that were similar to what was going on with my stuff, but it seems that what worked for others, didn't really do anyhting for me

You need to make the getreq function const by adding the keyword const after the parameter list parentheses, e.g.

Code:

int getreq() const;

That tells the compiler that the function won't change the state of the object, which is what the compiler needs to know before it allows you to call it from a const object (or a reference to a const object).

Actually, in this case a plain, non-member function should be fine. No need for static or friend.