src/test/ui/run-pass/issues/issue-39808.rs

   1 // Copyright 2016 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // run-pass
  12 #![allow(unreachable_code)]
  13
  14 // Regression test for #39808. The type parameter of `Owned` was
  15 // considered to be "unconstrained" because the type resulting from
  16 // `format!` (`String`) was not being propagated upward, owing to the
  17 // fact that the expression diverges.
  18
  19 use std::borrow::Cow;
  20
  21 fn main() {
  22     let _ = if false {
  23         Cow::Owned(format!("{:?}", panic!()))
  24     } else {
  25         Cow::Borrowed("")
  26     };
  27 }