diff options
Diffstat (limited to 'src/test/ui/run-pass/array-slice-vec/variance-vec-covariant.rs')
| -rw-r--r-- | src/test/ui/run-pass/array-slice-vec/variance-vec-covariant.rs | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/src/test/ui/run-pass/array-slice-vec/variance-vec-covariant.rs b/src/test/ui/run-pass/array-slice-vec/variance-vec-covariant.rs new file mode 100644 index 00000000000..caec6df5a4d --- /dev/null +++ b/src/test/ui/run-pass/array-slice-vec/variance-vec-covariant.rs @@ -0,0 +1,28 @@ +// Copyright 2015 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 that vec is now covariant in its argument type. + +#![allow(dead_code)] + +fn foo<'a,'b>(v1: Vec<&'a i32>, v2: Vec<&'b i32>) -> i32 { + bar(v1, v2).cloned().unwrap_or(0) // only type checks if we can intersect 'a and 'b +} + +fn bar<'c>(v1: Vec<&'c i32>, v2: Vec<&'c i32>) -> Option<&'c i32> { + v1.get(0).cloned().or_else(|| v2.get(0).cloned()) +} + +fn main() { + let x = 22; + let y = 44; + assert_eq!(foo(vec![&x], vec![&y]), 22); + assert_eq!(foo(vec![&y], vec![&x]), 44); +} |
