syntax_data: {"ast_node_type":"import","tokens":[{"end":80,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     ///   expression like `x[1][{x = y; 2}]`. We use fake borrows here to ensure
context_before:     /// * We need to ensure that the bounds check can't be invalidated using an
context_after:     ///   that this is the case.