syntax_data: {"ast_node_type":"other","tokens":[{"end":34,"kind":"keyword","start":0,"text":"Ok((valtree,"}]}
source_snippet:             Ok((valtree, ty)) => {
context_before:         let valtree = match self.eval_unevaluated_mir_constant_to_valtree(constant) {
context_after:                 // Defensively check that the type is monomorphic.