mirror of https://github.com/rust-lang/rust
25 lines
632 B
Rust
25 lines
632 B
Rust
//@ compile-flags: --crate-type=lib
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//@ check-pass
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pub trait Widget<E> {
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fn boxed<'w>(self) -> Box<dyn WidgetDyn<E> + 'w>
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where
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Self: Sized + 'w;
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}
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pub trait WidgetDyn<E> {}
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impl<T, E> WidgetDyn<E> for T where T: Widget<E> {}
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impl<E> Widget<E> for dyn WidgetDyn<E> + '_ {
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fn boxed<'w>(self) -> Box<dyn WidgetDyn<E> + 'w>
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where
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Self: Sized + 'w,
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{
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// Even though this is illegal to const evaluate, this should never
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// trigger an ICE because it can never be called from actual code
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// (due to the trivially false where-clause predicate).
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Box::new(self)
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}
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}
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