Macro impl_static_slab_allocatable 

macro_rules! impl_static_slab_allocatable {
    ($ty:ty, $lock:ty, $slab_size:expr, $allocator:expr) => { ... };
    ($ty:ty, $lock:ty, $slab_size:expr, $allocator:expr, $track_obj_count:expr) => { ... };
}

Macro to implement StaticSlabAllocated and Recyclable for a struct.