diff options
Diffstat (limited to 'src/test/ui/traits/trait-upcasting/lifetime.rs')
-rw-r--r-- | src/test/ui/traits/trait-upcasting/lifetime.rs | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/src/test/ui/traits/trait-upcasting/lifetime.rs b/src/test/ui/traits/trait-upcasting/lifetime.rs new file mode 100644 index 000000000..f029a6f08 --- /dev/null +++ b/src/test/ui/traits/trait-upcasting/lifetime.rs @@ -0,0 +1,95 @@ +// run-pass + +#![feature(trait_upcasting)] +#![allow(incomplete_features)] + +trait Foo: PartialEq<i32> + std::fmt::Debug + Send + Sync { + fn a(&self) -> i32 { + 10 + } + + fn z(&self) -> i32 { + 11 + } + + fn y(&self) -> i32 { + 12 + } +} + +trait Bar: Foo { + fn b(&self) -> i32 { + 20 + } + + fn w(&self) -> i32 { + 21 + } +} + +trait Baz: Bar { + fn c(&self) -> i32 { + 30 + } +} + +impl Foo for i32 { + fn a(&self) -> i32 { + 100 + } +} + +impl Bar for i32 { + fn b(&self) -> i32 { + 200 + } +} + +impl Baz for i32 { + fn c(&self) -> i32 { + 300 + } +} + +// Note: upcast lifetime means a shorter lifetime. +fn upcast_baz<'a: 'b, 'b, T>(v: Box<dyn Baz + 'a>, _l: &'b T) -> Box<dyn Baz + 'b> { + v +} +fn upcast_bar<'a: 'b, 'b, T>(v: Box<dyn Bar + 'a>, _l: &'b T) -> Box<dyn Bar + 'b> { + v +} +fn upcast_foo<'a: 'b, 'b, T>(v: Box<dyn Foo + 'a>, _l: &'b T) -> Box<dyn Foo + 'b> { + v +} + +fn main() { + let v = Box::new(1); + let l = &(); // dummy lifetime (shorter than `baz`) + + let baz: Box<dyn Baz> = v.clone(); + let u = upcast_baz(baz, &l); + assert_eq!(*u, 1); + assert_eq!(u.a(), 100); + assert_eq!(u.b(), 200); + assert_eq!(u.c(), 300); + + let baz: Box<dyn Baz> = v.clone(); + let bar: Box<dyn Bar> = baz; + let u = upcast_bar(bar, &l); + assert_eq!(*u, 1); + assert_eq!(u.a(), 100); + assert_eq!(u.b(), 200); + + let baz: Box<dyn Baz> = v.clone(); + let foo: Box<dyn Foo> = baz; + let u = upcast_foo(foo, &l); + assert_eq!(*u, 1); + assert_eq!(u.a(), 100); + + let baz: Box<dyn Baz> = v.clone(); + let bar: Box<dyn Bar> = baz; + let foo: Box<dyn Foo> = bar; + let u = upcast_foo(foo, &l); + assert_eq!(*u, 1); + assert_eq!(u.a(), 100); +} |