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20 lines
460 B
Rust
20 lines
460 B
Rust
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use std::sync::Mutex;
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static GLOBAL: Mutex<&'static str> = Mutex::new("global str");
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struct Foo<T>(T); // `T` is covariant.
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fn foo() {
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let mut x: Foo<for<'a> fn(&'a str)> = Foo(|_| ());
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let Foo(ref mut y): Foo<fn(&'static str)> = x;
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//~^ ERROR mismatched types
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*y = |s| *GLOBAL.lock().unwrap() = s;
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let string = String::from("i am shortlived");
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(x.0)(&string);
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}
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fn main() {
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foo();
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println!("{}", GLOBAL.lock().unwrap());
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}
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