entity_handle.h

#pragma once
 
#include <cstdint>
 
// EntityHandle lives in its own header so non-ECS layers (the render
// delta bridge in sim/delta_frame.h) can name entity identity without
// pulling in the agent pipeline; <tess/ecs/adapter.h> re-exports it.
namespace tess {

struct EntityHandle {
  std::uint64_t value = 0xFFFF'FFFF'FFFF'FFFFULL;
 
  [[nodiscard]] constexpr auto is_null() const noexcept -> bool {
    return value == 0xFFFF'FFFF'FFFF'FFFFULL;
  }
 
  friend constexpr auto operator==(EntityHandle, EntityHandle) noexcept
      -> bool = default;
};

inline constexpr EntityHandle kNullEntityHandle{};
 
}  // namespace tess