#pragma once

#include <compare>
#include <cstdint>
#include <stdexcept>

namespace fesa {

template <class Tag>
class EntityId final {
public:
    explicit constexpr EntityId(const std::int64_t value) : value_{value} {
        if (value < 0) {
            throw std::invalid_argument{"EntityId value must not be negative."};
        }
    }

    [[nodiscard]] constexpr std::int64_t value() const noexcept {
        return value_;
    }

    auto operator<=>(const EntityId&) const = default;

private:
    std::int64_t value_;
};

}  // namespace fesa