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Diffstat (limited to '')
-rw-r--r-- | src/test/ui/overloaded/overloaded-autoderef-vtable.rs | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/src/test/ui/overloaded/overloaded-autoderef-vtable.rs b/src/test/ui/overloaded/overloaded-autoderef-vtable.rs new file mode 100644 index 000000000..f8e6d1208 --- /dev/null +++ b/src/test/ui/overloaded/overloaded-autoderef-vtable.rs @@ -0,0 +1,39 @@ +// run-pass +#![allow(dead_code)] + +use std::ops::Deref; + +struct DerefWithHelper<H, T> { + helper: H, + value: T +} + +trait Helper<T> { + fn helper_borrow(&self) -> &T; +} + +impl<T> Helper<T> for Option<T> { + fn helper_borrow(&self) -> &T { + self.as_ref().unwrap() + } +} + +impl<T, H: Helper<T>> Deref for DerefWithHelper<H, T> { + type Target = T; + + fn deref(&self) -> &T { + self.helper.helper_borrow() + } +} + +struct Foo {x: isize} + +impl Foo { + fn foo(&self) -> isize {self.x} +} + +pub fn main() { + let x: DerefWithHelper<Option<Foo>, Foo> = + DerefWithHelper { helper: Some(Foo {x: 5}), value: Foo { x: 2 } }; + assert_eq!(x.foo(), 5); +} |