197     pub parent_chain: VMStackChain,
257         let parent_chain = VMStackChain::Absent;  in empty()
315     contref.parent_chain = VMStackChain::Absent;  in cont_new()
429 pub enum VMStackChain {  enum
445 impl VMStackChain {  implementation
448         matches!(self, VMStackChain::InitialStack(_))  in is_initial_stack()
479 pub struct ContinuationIterator(VMStackChain);
482 pub struct StackLimitsIterator(VMStackChain);
489             VMStackChain::Absent | VMStackChain::InitialStack(_) => None,  in next()
490             VMStackChain::Continuation(ptr) => {  in next()
504             VMStackChain::Absent => None,  in next()
505             VMStackChain::InitialStack(csi) => {  in next()
507                 self.0 = VMStackChain::Absent;  in next()
510             VMStackChain::Continuation(ptr) => {  in next()
687             size_of::<VMStackChain>(),  in check_vm_stack_chain_offsets()