strongly typed id

strongly_typed_id.cpp

#include <iostream>
#include <stdint.h>

class Area;
class Quest;

template <typename T, typename Meaning>
struct Explicit
{
    Explicit() {}
    Explicit(T value) : value(value) {}

    inline operator T () const { return value; }
    T value;
};

using AreaId = Explicit<uint16_t, Area>;
using QuestId = Explicit<uint16_t, Quest>;

int main() {
    AreaId areaId = 3;
    AreaId areaId2 = 5;
    QuestId questId = 4;

    areaId2 = areaId;
    // areaId2 = questId; // error

    return 0;
}