syntax_data: {"ast_node_type":"other","tokens":[{"end":89,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                                 // Can define opaque types as this is only reachable with
context_before:                             match self.infcx.at(&obligation.cause, obligation.param_env).eq(
context_after:                                 // `generic_const_exprs`