Unique ID generated by type in runtime in C++.

const int NO_INDEX = -1;

template <typename T>
struct StaticType
{
    static int type;
};
template <typename T> int StaticType<T>::type = NO_INDEX;
static int _uniqueType = 0;

struct UID
{
    template <typename T>
    static int Get()
    {
        if (StaticType<T>::type != NO_INDEX)
        {
            return StaticType<T>::type;
        }
        else
        {
            ++_uniqueType;
            StaticType<T>::type = _uniqueType;
        }

        return StaticType<T>::type;
    }

};