I am trying to implement a queue so that repeated objects can not be inserted. I have this implementation that I found but it gives me an error:
std::queue<punto> q;
std::set<std::reference_wrapper<punto>> s;
// to add:
void add(punto const & x)
{
if (s.find(x) == s.end())
{
q.push(x);
s.insert(std::ref(q.back())); // or "s.emplace(q.back());"
}
}
The s.find(x) tells me no overloaded function instance.
Indeed, std::set does not have a find method that you can use since it is a container that is already indexed (and unlike std::map has no key, then searching for an element does not make sense).
However, if you have a count method that works for your purposes:
if (s.count(x) == 0)
{
q.push(x);
s.insert(std::ref(q.back())); // or "s.emplace(q.back());"
}
Since set does not support duplicates, count could only return 0 or 1.