RefCountable

RefCountable is the lightweight atomic reference-counter base used by FLOX pools, handles, and other intrusive smart-pointer utilities.

class RefCountable {
public:
  void     retain()          noexcept;   // ++ref
  bool     release()         noexcept;   // --ref, returns true when it hits 0
  void     resetRefCount(uint32_t v = 0) noexcept;
  uint32_t refCount()  const noexcept;

protected:
  std::atomic<uint32_t> _refCount{0};    // starts at 0
};

Purpose

• Provide a thread-safe reference counter without virtuals.
• Integrate with pool::Handle<T> which calls retain()/release() to manage pooled objects.

Semantics

Method	Behaviour
retain()	Atomically increments _refCount. Debug assert guards overflow.
release()	Decrements; returns true when the count becomes zero (caller should recycle/free the object). Aborts in debug if called on a zero count.
resetRefCount(v)	Directly sets the counter (used when an object is re-acquired from a pool).
refCount()	Read-only accessor.

Usage Pattern

struct MyEvent : pool::PoolableBase<MyEvent> { /* … */ };

pool::Pool<MyEvent, 1024> pool;
auto h = pool.acquire();   // retain = 1
auto h2 = h;               // retain = 2
h.reset();                 // retain = 1
// last handle out of scope → release() returns true → object returns to pool

Notes

• Relies on std::atomic<uint32_t> with relaxed / acq_rel ordering for minimal overhead.
• static_assert(concepts::RefCountable<RefCountable>) guarantees the class satisfies its own concept.