zecsy/zecsy.hpp

#pragma once
#include <cstdint>
#include <bitset>
#include <numeric>

#ifndef MAX_ZECSY_ENTITIES
    #define MAX_ZECSY_ENTITIES 65536
#endif // !MAX_ZECSY_ENTITIES


namespace zecsy 
{
    using entity_id = uint64_t;

    class world final
    {
    public:
        world() = default;
        world(const world &) = default;
        world(world &&) = default;
        world &operator=(const world &) = default;
        world &operator=(world &&) = default;
   
        entity_id make_entity();
        void destroy_entity(entity_id e);
        bool is_alive(entity_id e) const; 
    private:
        std::bitset<MAX_ZECSY_ENTITIES> entities_bitset;
        entity_id entity_counter = 0;
    };

    inline entity_id world::make_entity()
    {
        auto id = ++entity_counter;
        entities_bitset.set(id);
        return id;
    }

    inline void world::destroy_entity(entity_id e)
    {
        entities_bitset.reset(e);
    }

    inline bool world::is_alive(entity_id e) const
    {
        return entities_bitset.test(e);
    }
};