33 lines
617 B
Rust
33 lines
617 B
Rust
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type Result<T, E = Error> = ::std::result::Result<T, E>;
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struct Error;
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trait ForEach {
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type Input;
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fn for_each<F, U>(self, f: F)
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where
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F: FnOnce(Self::Input) -> U;
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}
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impl<T> ForEach for A<T> {
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type Input = T;
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fn for_each<F, U>(self, f: F)
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where
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F: FnOnce(Self::Input) -> U,
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{
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todo!()
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}
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}
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struct A<T>(T);
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fn main() {
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let a = A(Result::Ok(Result::Ok(()))); //~ ERROR type annotations needed
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a.for_each(|a: Result<_>| {
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let f = || match a {
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Ok(Ok(a)) => {}
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Ok(Err(a)) => {}
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Err(a) => {}
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};
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});
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}
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