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Diffstat (limited to 'src/test/ui/compile-fail-migration/overlap-marker-trait.rs')
| -rw-r--r-- | src/test/ui/compile-fail-migration/overlap-marker-trait.rs | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/src/test/ui/compile-fail-migration/overlap-marker-trait.rs b/src/test/ui/compile-fail-migration/overlap-marker-trait.rs new file mode 100644 index 00000000000..a649ae25f34 --- /dev/null +++ b/src/test/ui/compile-fail-migration/overlap-marker-trait.rs @@ -0,0 +1,41 @@ +// Copyright 2017 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// Test for RFC 1268: we allow overlapping impls of marker traits, +// that is, traits without items. In this case, a type `T` is +// `MyMarker` if it is either `Debug` or `Display`. This test just +// checks that we don't consider **all** types to be `MyMarker`. See +// also the companion test in +// `run-pass/overlap-permitted-for-marker-traits.rs`. + +#![feature(overlapping_marker_traits)] +#![feature(optin_builtin_traits)] + +use std::fmt::{Debug, Display}; + +trait Marker {} + +impl<T: Debug> Marker for T {} +impl<T: Display> Marker for T {} + +fn is_marker<T: Marker>() { } + +struct NotDebugOrDisplay; + +fn main() { + // Debug && Display: + is_marker::<i32>(); + + // Debug && !Display: + is_marker::<Vec<i32>>(); + + // !Debug && !Display + is_marker::<NotDebugOrDisplay>(); //~ ERROR +} |
