mirror of https://github.com/rust-lang/rust
38 lines
974 B
Rust
38 lines
974 B
Rust
// Check that child trait who only has items via its *parent* trait
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// does cause dropck to inject extra region constraints.
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#![allow(non_camel_case_types)]
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trait Parent { fn foo(&self); }
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trait Child: Parent { }
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impl Parent for i32 { fn foo(&self) { } }
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impl<'a> Parent for &'a D_Child<i32> {
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fn foo(&self) {
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println!("accessing child value: {}", self.0);
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}
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}
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impl Child for i32 { }
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impl<'a> Child for &'a D_Child<i32> { }
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struct D_Child<T:Child>(T);
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impl <T:Child> Drop for D_Child<T> { fn drop(&mut self) { self.0.foo() } }
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fn f_child() {
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// `_d` and `d1` are assigned the *same* lifetime by region inference ...
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let (_d, d1);
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d1 = D_Child(1);
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// ... we store a reference to `d1` within `_d` ...
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_d = D_Child(&d1);
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//~^ ERROR `d1` does not live long enough
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// ... dropck *should* complain, because Drop of _d could (and
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// does) access the already dropped `d1` via the `foo` method.
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}
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fn main() {
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f_child();
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}
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