syntax_data: {"ast_node_type":"variable","tokens":[{"end":97,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:     let structural_peq_def_id = infcx.tcx.require_lang_item(LangItem::StructuralPeq, cause.span);
context_before:     // require `#[derive(PartialEq)]`
context_after:     ocx.register_bound(cause.clone(), ty::ParamEnv::empty(), adt_ty, structural_peq_def_id);