{"ast_node_type":"other","tokens":[{"end":85,"kind":"keyword","start":0,"text":"debug_assert!(!source_ty.has_param(),"}]}
    debug_assert!(!source_ty.has_param(), "{source_ty} should be fully monomorphic");
    let typing_env = ty::TypingEnv::fully_monomorphized();
    debug_assert!(!target_ty.has_param(), "{target_ty} should be fully monomorphic");