syntax_data: {"ast_node_type":"other","tokens":[{"end":60,"kind":"keyword","start":0,"text":"Box::new(AggregateKind::Array(elem_ty)),"}]}
source_snippet:                     Box::new(AggregateKind::Array(elem_ty)),
context_before:                 Ok(Rvalue::Aggregate(
context_after:                     fields.iter().map(|e| self.parse_operand(*e)).collect::<Result<_, _>>()?