37 lines
687 B
Rust
37 lines
687 B
Rust
#![feature(type_alias_impl_trait)]
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type FooArg<'a> = &'a dyn ToString;
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type FooRet = impl std::fmt::Debug;
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type FooItem = Box<dyn Fn(FooArg) -> FooRet>;
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type Foo = impl Iterator<Item = FooItem>;
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#[repr(C)]
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struct Bar(u8);
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impl Iterator for Bar {
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type Item = FooItem;
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fn next(&mut self) -> Option<Self::Item> {
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Some(Box::new(quux))
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}
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}
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fn quux(st: FooArg) -> FooRet {
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Some(st.to_string())
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}
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fn ham() -> Foo {
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Bar(1)
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}
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fn oof(_: Foo) -> impl std::fmt::Debug {
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let mut bar = ham();
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let func = bar.next().unwrap();
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return func(&"oof"); //~ ERROR opaque type's hidden type cannot be another opaque type
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}
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fn main() {
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let _ = oof(ham());
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}
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