syntax_data: {"ast_node_type":"other","tokens":[{"end":57,"kind":"keyword","start":0,"text":"inputs_and_output:"}]}
source_snippet:             inputs_and_output: sig_tys.inputs_and_output,
context_before:         self.map_bound(|sig_tys| FnSig {
context_after:             c_variadic: hdr.c_variadic,