syntax_data: {"ast_node_type":"other","tokens":[{"end":72,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                 // If the metadata is a 1-zst, then the pointer is thin.
context_before:                 let metadata_layout = cx.layout_of(metadata_ty)?;
context_after:                 if metadata_layout.is_1zst() {