39 lines
1.4 KiB
Rust
39 lines
1.4 KiB
Rust
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// Regression test for #53548. The `Box<dyn Trait>` type below is
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// expanded to `Box<dyn Trait + 'static>`, but the generator "witness"
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// that results is `for<'r> { Box<dyn Trait + 'r> }`. The WF code was
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// encountering an ICE (when debug-assertions were enabled) and an
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// unexpected compilation error (without debug-asserions) when trying
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// to process this `'r` region bound. In particular, to be WF, the
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// region bound must meet the requirements of the trait, and hence we
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// got `for<'r> { 'r: 'static }`. This would ICE because the `Binder`
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// constructor we were using was assering that no higher-ranked
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// regions were involved (because the WF code is supposed to skip
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// those). The error (if debug-asserions were disabled) came because
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// we obviously cannot prove that `'r: 'static` for any region `'r`.
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// Pursuant with our "lazy WF" strategy for higher-ranked regions, the
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// fix is not to require that `for<'r> { 'r: 'static }` holds (this is
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// also analogous to what we would do for higher-ranked regions
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// appearing within the trait in other positions).
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//
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// compile-pass
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#![feature(generators)]
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use std::cell::RefCell;
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use std::rc::Rc;
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trait Trait: 'static {}
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struct Store<C> {
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inner: Rc<RefCell<Option<C>>>,
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}
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fn main() {
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Box::new(static move || {
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let store = Store::<Box<dyn Trait>> {
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inner: Default::default(),
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};
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yield ();
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});
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}
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