syntax_data: {"ast_node_type":"other","tokens":[{"end":36,"kind":"keyword","start":0,"text":"for"}]}
source_snippet:                 for arg in uv.args {
context_before:                     .create_err(ConstPatternDependsOnGenericParameter { span: self.span });
context_after:                     if let ty::GenericArgKind::Type(ty) = arg.kind()