syntax_data: {"ast_node_type":"other","tokens":[{"end":81,"kind":"keyword","start":0,"text":"self.require_sized(subty,"}]}
source_snippet:                 self.require_sized(subty, ObligationCauseCode::SliceOrArrayElem);
context_before:             ty::Array(subty, len) => {
context_after:                 // Note that the len being WF is implicitly checked while visiting.