{"ast_node_type":"other","tokens":[{"end":50,"kind":"keyword","start":0,"text":"alloc:"}]}
    alloc: &'a mut Allocation<Prov, Extra, Bytes>,
pub struct AllocRefMut<'a, 'tcx, Prov: Provenance, Extra, Bytes: AllocBytes = Box<[u8]>> {
    range: AllocRange,