8a461d940c
suggest adding a where-clause when there is an unmet trait-bound that can be satisfied if some type can implement it.
40 lines
1.3 KiB
Rust
40 lines
1.3 KiB
Rust
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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#![feature(unboxed_closures)]
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#![feature(box_syntax)]
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fn needs_fn<F>(x: F) where F: Fn(isize) -> isize {}
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fn main() {
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let _: () = (box |_: isize| {}) as Box<FnOnce(isize)>;
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//~^ ERROR mismatched types
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//~| expected `()`
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//~| found `Box<std::ops::FnOnce(isize)>`
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//~| expected ()
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//~| found box
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let _: () = (box |_: isize, isize| {}) as Box<Fn(isize, isize)>;
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//~^ ERROR mismatched types
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//~| expected `()`
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//~| found `Box<std::ops::Fn(isize, isize)>`
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//~| expected ()
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//~| found box
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let _: () = (box || -> isize { unimplemented!() }) as Box<FnMut() -> isize>;
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//~^ ERROR mismatched types
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//~| expected `()`
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//~| found `Box<std::ops::FnMut() -> isize>`
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//~| expected ()
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//~| found box
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needs_fn(1);
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//~^ ERROR : std::ops::Fn<(isize,)>`
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//~| ERROR : std::ops::FnOnce<(isize,)>`
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}
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