let method_type = match method {
Some(ref method) => method.ty,
None => {
- fcx.tcx().sess.span_err(iterator_expr.span,
- format!("`for` loop expression has type `{}` which does \
- not implement the `Iterator` trait",
- fcx.infcx().ty_to_string(expr_type)).as_slice());
+ let true_expr_type = fcx.infcx().resolve_type_vars_if_possible(expr_type);
+
+ if !ty::type_is_error(true_expr_type) {
+ let ty_string = fcx.infcx().ty_to_string(true_expr_type);
+ fcx.tcx().sess.span_err(iterator_expr.span,
+ format!("`for` loop expression has type `{}` which does \
+ not implement the `Iterator` trait",
+ ty_string).as_slice());
+ }
ty::mk_err()
}
};
--- /dev/null
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+pub fn main() {
+ let x = () + (); //~ ERROR binary operation
+
+ // this shouldn't have a flow-on error:
+ for _ in x {}
+}