syntax_data: {"ast_node_type":"other","tokens":[{"end":63,"kind":"keyword","start":0,"text":"//!"}]}
source_snippet: //! - `as_operand` -> either invokes `as_constant` or `as_temp`
context_before: //! - `as_rvalue` -> fallback is to create an Operand with `as_operand` and use `Rvalue::use`
context_after: //! - `as_constant` -> (no fallback)