syntax_data: {"ast_node_type":"other","tokens":[{"end":35,"kind":"keyword","start":0,"text":"for"}]}
source_snippet:                 for (pred, span) in
context_before:                 // only generic parameters, and thus instantiating would not give us more information.
context_after:                     self.tcx.explicit_item_bounds(alias_ty.def_id).iter_identity_copied()