syntax_data: {"ast_node_type":"other","tokens":[{"end":78,"kind":"keyword","start":0,"text":"//!"}]}
source_snippet: //! - `as_temp` -- evaluates into a temporary; this is similar to `as_operand`
context_before: //!   suitable for use as an argument to an `Rvalue`
context_after: //!   except it always returns a fresh place, even for constants