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27 lines
536 B
Rust
27 lines
536 B
Rust
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#![feature(thin_box)]
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// run-pass
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use std::boxed::ThinBox;
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use std::error::Error;
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use std::ops::Deref;
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use std::fmt;
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fn main() {
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let expected = "Foo error!";
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let a: ThinBox<dyn Error> = ThinBox::new_unsize(Foo(expected));
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let a = a.deref();
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let msg = a.to_string();
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assert_eq!(expected, msg);
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}
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#[derive(Debug)]
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#[repr(align(1024))]
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struct Foo(&'static str);
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impl fmt::Display for Foo {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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write!(f, "{}", self.0)
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}
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}
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impl Error for Foo {}
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