gistfile1.cpp

struct term_comparator
{
    template <typename T>
    bool operator()(const T &p1, const T &p2) const noexcept
    {
        return p1.first == p2.first;
    }
};

// This is the full definition of the hash set.
piranha::hash_set<std::pair<....>,std::hash<std::pair<....>>,term_comparator>;