26 lines
778 B
Rust
26 lines
778 B
Rust
// Copyright 2015 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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struct A<F: FnOnce()->T,T>(F::Output);
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struct B<F: FnOnce()->T,T>(A<F,T>);
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// Removing Option causes it to compile.
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fn foo<T,F: FnOnce()->T>(f: F) -> Option<B<F,T>> {
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Some(B(A(f())))
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}
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fn main() {
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let v = (|| foo(||4))();
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match v {
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Some(B(A(4))) => {},
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_ => unreachable!()
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}
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}
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