EntityId.h

#pragma once
 
#include "mc/_HeaderOutputPredefine.h"
 
#include "mc/deps/ecs/EntityIdTraits.h"
 
// entt v4 constrains `entt::entt_traits` with the `entity_like` concept, which is
// only satisfied when `entt::internal::entt_traits` is defined for the type. It is
// also the traits the generic `entt::entt_traits` is built from, so specializing it
// makes `entt::entt_traits<EntityId>` resolve to `basic_entt_traits<EntityIdTraits>`.
namespace entt::internal {
template <>
struct entt_traits<EntityId> : EntityIdTraits {};
} // namespace entt::internal
 
namespace entt {
 
template <>
struct entt_traits<EntityId> : basic_entt_traits<EntityIdTraits> {
    using base_type = basic_entt_traits<EntityIdTraits>;
 
    static constexpr std::size_t page_size = 2048;
};
 
} // namespace entt
 
class EntityId : public entt::entt_traits<EntityId> {
public:
    entity_type mRawId{entt::null};
 
    [[nodiscard]] constexpr EntityId() = default;
 
    [[nodiscard]] constexpr EntityId(entity_type rawId) : mRawId(rawId) {}
 
    [[nodiscard]] constexpr bool isNull() const { return *this == entt::null; }
 
    [[nodiscard]] constexpr operator entity_type() const { return mRawId; }
};