I have a class representing a user called Nick and I want to use std::find_if on it, where I want to find if the userlist vector has an object incl
You have to define operator== with two Objects outside your class, as a tool function, not a member.
Then to make it friend just put the declaration of the function inside the class.
try something like this:
class Nick {
public:
friend bool operator== ( const Nick &n1, const Nick &n2);
};
bool operator== ( const Nick &n1, const Nick &n2)
{
return n1.username == n2.username;
}
Also your find should look like this:
std::find(userlist.begin(), userlist.end(), Nick(username, false) );
No need of "new".