type UserArena struct {
	arena *userArena
}

func NewUserArena() *UserArena {
	return &UserArena{newUserArena()}
}

func (a *UserArena) New(out *any) {
	i := efaceOf(out)
	typ := i._type
	if typ.Kind_&abi.KindMask != abi.Pointer {
		panic("new result of non-ptr type")
	}
	typ = (*ptrtype)(unsafe.Pointer(typ)).Elem
	i.data = a.arena.new(typ)
}

func (t *timer) hchan() *hchan {
	if !t.isChan {
		badTimer()
	}
	// Note: t.arg is a chan time.Time,
	// and runtime cannot refer to that type,
	// so we cannot use a type assertion.
	return (*hchan)(efaceOf(&t.arg).data)
}

// updateHeap updates t as directed by t.state, updating t.state
// and returning a bool indicating whether the state (and ts.heap[0].when) changed.