syntax_data: {"ast_node_type":"variable","tokens":[{"end":47,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let width = lit_ty.primitive_size(tcx);
context_before:     let trunc = |n| {
context_after:         trace!("trunc {} with size {} and shift {}", n, width.bits(), 128 - width.bits());