diff options
Diffstat (limited to 'src/test/ui/self/object-safety-sized-self-by-value-self.rs')
-rw-r--r-- | src/test/ui/self/object-safety-sized-self-by-value-self.rs | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/src/test/ui/self/object-safety-sized-self-by-value-self.rs b/src/test/ui/self/object-safety-sized-self-by-value-self.rs new file mode 100644 index 000000000..43b1d8b91 --- /dev/null +++ b/src/test/ui/self/object-safety-sized-self-by-value-self.rs @@ -0,0 +1,39 @@ +// run-pass +#![allow(unused_mut)] +// Check that a trait is still object-safe (and usable) if it has +// methods with by-value self so long as they require `Self : Sized`. + + +trait Counter { + fn tick(&mut self) -> u32; + fn get(self) -> u32 where Self : Sized; +} + +struct CCounter { + c: u32 +} + +impl Counter for CCounter { + fn tick(&mut self) -> u32 { self.c += 1; self.c } + fn get(self) -> u32 where Self : Sized { self.c } +} + +fn tick1<C:Counter>(mut c: C) -> u32 { + tick2(&mut c); + c.get() +} + +fn tick2(c: &mut dyn Counter) { + tick3(c); +} + +fn tick3<C:?Sized+Counter>(c: &mut C) { + c.tick(); + c.tick(); +} + +fn main() { + let mut c = CCounter { c: 0 }; + let value = tick1(c); + assert_eq!(value, 2); +} |