syntax_data: {"ast_node_type":"other","tokens":[{"end":79,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                 // for borrow expressions, so we cannot create an `RValue` that
context_before:                 // We don't do this in `as_rvalue` because we use `as_place`
context_after:                 // remains valid across user code. `as_rvalue` is usually called