mirror of https://github.com/rust-lang/rust
30 lines
698 B
Rust
30 lines
698 B
Rust
trait Foo {}
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impl<F> Foo for F where F: Fn(&i32) -> &i32 {}
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fn take_foo(_: impl Foo) {}
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fn main() {
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take_foo(|a| a);
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//~^ ERROR implementation of `FnOnce` is not general enough
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//~| ERROR implementation of `Fn` is not general enough
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take_foo(|a: &i32| a);
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//~^ ERROR lifetime may not live long enough
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//~| ERROR mismatched types
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take_foo(|a: &i32| -> &i32 { a });
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//~^ ERROR lifetime may not live long enough
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//~| ERROR mismatched types
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// OK
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take_foo(identity(|a| a));
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take_foo(identity(|a: &i32| a));
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take_foo(identity(|a: &i32| -> &i32 { a }));
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fn identity<F>(t: F) -> F
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where
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F: Fn(&i32) -> &i32,
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{
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t
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}
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}
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