syntax_data: {"ast_node_type":"variable","tokens":[{"end":66,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                     let field_off = off + layout.fields.offset(i);
context_before:                 for i in 0..layout.fields.count() {
context_after:                     classify(cx, layout.field(cx, i), cls, field_off)?;