syntax_data: {"ast_node_type":"other","tokens":[{"end":93,"kind":"keyword","start":0,"text":"Self::prefixed([Some(a),"}]}
source_snippet:         Self::prefixed([Some(a), None, None, None, None, None, None, None], Uniform::from(b))
context_before:     pub fn pair(a: Reg, b: Reg) -> CastTarget {
context_after:     }