8a461d940c
suggest adding a where-clause when there is an unmet trait-bound that can be satisfied if some type can implement it.
39 lines
1.3 KiB
Rust
39 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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// Test interaction between unboxed closure sugar and default type
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// parameters (should be exactly as if angle brackets were used).
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#![feature(unboxed_closures)]
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#![allow(dead_code)]
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trait Foo<T,V=T> {
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type Output;
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fn dummy(&self, t: T, v: V);
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}
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trait Eq<X: ?Sized> { fn same_types(&self, x: &X) -> bool { true } }
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impl<X: ?Sized> Eq<X> for X { }
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fn eq<A: ?Sized,B: ?Sized>() where A : Eq<B> { }
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fn test<'a,'b>() {
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// Parens are equivalent to omitting default in angle.
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eq::< Foo<(isize,),Output=()>, Foo(isize) >();
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// In angle version, we supply something other than the default
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eq::< Foo<(isize,),isize,Output=()>, Foo(isize) >();
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//~^ ERROR E0277
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// Supply default explicitly.
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eq::< Foo<(isize,),(isize,),Output=()>, Foo(isize) >();
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}
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fn main() { }
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