syntax_data: {"ast_node_type":"other","tokens":[{"end":35,"kind":"keyword","start":0,"text":"kind"}]}
source_snippet:             kind => unimplemented!(
context_before:             ty::Tuple(fields) => fields[i.as_usize()],
context_after:                 "only a subset of `Ty::ty_and_layout_field`'s functionality is implemented. implementation needed for {:?}",