mirror of https://github.com/rust-lang/rust
41 lines
829 B
Rust
41 lines
829 B
Rust
// Test that we can deduce when projections like `T::Item` outlive the
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// function body. Test that this does not imply that `T: 'a` holds.
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//@ compile-flags:-Zverbose-internals
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use std::cell::Cell;
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fn twice<F, T>(mut value: T, mut f: F)
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where
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F: FnMut(&T, Cell<&Option<T::Item>>),
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T: Iterator,
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{
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let mut n = value.next();
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f(&value, Cell::new(&n));
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f(&value, Cell::new(&n));
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}
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fn generic1<T: Iterator>(value: T) {
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// No error here:
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twice(value, |value_ref, item| invoke1(item));
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}
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fn invoke1<'a, T>(x: Cell<&'a Option<T>>)
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where
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T: 'a,
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{
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}
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fn generic2<T: Iterator>(value: T) {
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twice(value, |value_ref, item| invoke2(value_ref, item));
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//~^ ERROR the parameter type `T` may not live long enough
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}
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fn invoke2<'a, T, U>(a: &T, b: Cell<&'a Option<U>>)
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where
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T: 'a,
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{
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}
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fn main() {}
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