syntax_data: {"ast_node_type":"other","tokens":[{"end":32,"kind":"keyword","start":0,"text":"Str"}]}
source_snippet:             Str => tcx.types.u8,
context_before:             Array(ty, _) | Slice(ty) => *ty,
context_after:             _ => bug!("`sequence_element_type` called on non-sequence value: {}", self),