syntax_data: {"ast_node_type":"other","tokens":[{"end":75,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// For slices it'll be `Operand::Move` of a local using `PtrMetadata`.
context_before:     /// For arrays it'll be `Operand::Constant` with the actual length;
context_after:     fn len_of_slice_or_array(