ref.hpp

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#pragma once
 
namespace flecs
{
 
template <typename T>
struct ref {
    ref() : m_world(nullptr), m_ref{} { }
 
    ref(world_t *world, entity_t entity, flecs::id_t id = 0)
        : m_ref()
    {
        // the world we were called with may be a stage; convert it to a world
        // here if that is the case
        m_world = world ? const_cast<flecs::world_t *>(ecs_get_world(world))
            : nullptr;
        if (!id) {
            id = _::cpp_type<T>::id(world);
        }
 
        ecs_assert(_::cpp_type<T>::size() != 0, ECS_INVALID_PARAMETER, NULL);
 
        m_ref = ecs_ref_init_id(m_world, entity, id);
    }
 
    T* operator->() {
        T* result = static_cast<T*>(ecs_ref_get_id(
            m_world, &m_ref, this->m_ref.id));
 
        ecs_assert(result != NULL, ECS_INVALID_PARAMETER, NULL);
 
        return result;
    }
 
    T* get() {
        return static_cast<T*>(ecs_ref_get_id(
            m_world, &m_ref, this->m_ref.id));
    }
 
    T* try_get() {
        if (!m_world || !m_ref.entity) {
            return nullptr;
        }
 
        return get();
    }
 
    flecs::entity entity() const;
 
private:
    world_t *m_world;
    flecs::ref_t m_ref;
};
 
}