syntax_data: {"ast_node_type":"other","tokens":[{"end":29,"kind":"keyword","start":0,"text":"//!"}]}
source_snippet: //!   should be uninitialized
context_before: //! - `expr_into_dest` -- writes the value into a specific location, which
context_after: //! - `as_operand` -- evaluates the value and yields an `Operand`,