32 lines
798 B
Rust
32 lines
798 B
Rust
//@ run-pass
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// Test that we can't ignore lifetimes by going through Any.
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use std::any::Any;
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struct Foo<'a>(&'a str);
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fn good(s: &String) -> Foo { Foo(s) }
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fn bad1(s: String) -> Option<&'static str> {
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let a: Box<dyn Any> = Box::new(good as fn(&String) -> Foo);
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a.downcast_ref::<fn(&String) -> Foo<'static>>().map(|f| f(&s).0)
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}
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trait AsStr<'a, 'b> {
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fn get(&'a self) -> &'b str;
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}
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impl<'a> AsStr<'a, 'a> for String {
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fn get(&'a self) -> &'a str { self }
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}
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fn bad2(s: String) -> Option<&'static str> {
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let a: Box<dyn Any> = Box::new(Box::new(s) as Box<dyn for<'a> AsStr<'a, 'a>>);
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a.downcast_ref::<Box<dyn for<'a> AsStr<'a, 'static>>>().map(|x| x.get())
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}
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fn main() {
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assert_eq!(bad1(String::from("foo")), None);
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assert_eq!(bad2(String::from("bar")), None);
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}
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