mirror of https://github.com/rust-lang/rust
35 lines
905 B
Rust
35 lines
905 B
Rust
//@ run-pass
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// Test that we are able to resolve conditional dispatch. Here, the
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// blanket impl for T:Copy coexists with an impl for Box<T>, because
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// Box does not impl Copy.
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trait Get {
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fn get(&self) -> Self;
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}
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trait MyCopy { fn copy(&self) -> Self; }
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impl MyCopy for u16 { fn copy(&self) -> Self { *self } }
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impl MyCopy for u32 { fn copy(&self) -> Self { *self } }
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impl MyCopy for i32 { fn copy(&self) -> Self { *self } }
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impl<T:Copy> MyCopy for Option<T> { fn copy(&self) -> Self { *self } }
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impl<T:MyCopy> Get for T {
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fn get(&self) -> T { self.copy() }
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}
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impl Get for Box<i32> {
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fn get(&self) -> Box<i32> { Box::new(get_it(&**self)) }
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}
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fn get_it<T:Get>(t: &T) -> T {
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(*t).get()
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}
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fn main() {
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assert_eq!(get_it(&1_u32), 1_u32);
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assert_eq!(get_it(&1_u16), 1_u16);
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assert_eq!(get_it(&Some(1_u16)), Some(1_u16));
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assert_eq!(get_it(&Box::new(1)), Box::new(1));
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}
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