syntax_data: {"ast_node_type":"variable","tokens":[{"end":62,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:             let selcx = &mut SelectionContext::new(ocx.infcx);
context_before:             debug_assert!(!ocx.infcx.next_trait_solver());
context_after:             let cause = ObligationCause::dummy();