Using Data structure as a key for std::set and std::unordered_set

It is necessary to make the user-defined structure Data usable as a key in both an ordered container std::set and an unordered container std::unordered_set. To do this, you should implement the required comparison operators and hash function, after which the code example will compile and work successfully.

#include <set>
#include <iostream>
#include <unordered_set>

struct Data {
    int value;
};

int main(int argc, char** argv)
{
    std::set<Data> dataSet;
    std::unordered_set<Data> dataUSet;
    return EXIT_SUCCESS;
}