| // Copyright 2016 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. |
| |
| #![feature(question_mark, question_mark_carrier)] |
| |
| // Test that type inference fails where there are multiple possible return types |
| // for the `?` operator. |
| |
| fn f(x: &i32) -> Result<i32, ()> { |
| Ok(*x) |
| } |
| |
| fn g() -> Result<Vec<i32>, ()> { |
| let l = [1, 2, 3, 4]; |
| l.iter().map(f).collect()? //~ ERROR type annotations required: cannot resolve |
| } |
| |
| fn main() { |
| g(); |
| } |
