mirror of https://github.com/rust-lang/rust.git
30 lines
672 B
Rust
30 lines
672 B
Rust
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// Test for RFC 1268: we allow overlapping impls of marker traits,
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// that is, traits with #[marker]. In this case, a type `T` is
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// `MyMarker` if it is either `Debug` or `Display`. This test just
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// checks that we don't consider **all** types to be `MyMarker`.
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#![feature(marker_trait_attr)]
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use std::fmt::{Debug, Display};
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#[marker]
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trait Marker {}
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impl<T: Debug> Marker for T {}
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impl<T: Display> Marker for T {}
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fn is_marker<T: Marker>() { }
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struct NotDebugOrDisplay;
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fn main() {
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// Debug && Display:
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is_marker::<i32>();
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// Debug && !Display:
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is_marker::<Vec<i32>>();
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// !Debug && !Display
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is_marker::<NotDebugOrDisplay>(); //~ ERROR
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}
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