syntax_data: {"ast_node_type":"impl","tokens":[{"end":75,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                     // impl then check whether the field types need `Drop`.
context_before:                     // `ManuallyDrop`. If it's a struct or enum without a `Drop`
context_after:                     ty::Adt(adt_def, args) => {