Fix and test variance of BTreeMap and its companion structs.

1 files changed, 56 insertions, 0 deletions

diff --git a/src/test/compile-fail/variance-btree-invariant-types.rs b/src/test/compile-fail/variance-btree-invariant-types.rs
new file mode 100644
index 00000000000..ad94a3865ac
--- /dev/null
+++ b/src/test/compile-fail/variance-btree-invariant-types.rs
@@ -0,0 +1,56 @@
+// Copyright 2016 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.
+
+#![feature(rustc_attrs)]
+
+use std::collections::btree_map::{IterMut, OccupiedEntry, VacantEntry};
+
+macro_rules! test_invariant {
+    { $m:ident $t:ident } => {
+        mod $m {
+            use std::collections::btree_map::{IterMut, OccupiedEntry, VacantEntry};
+
+            fn not_covariant_key<'a, 'min,'max>(v: $t<'a, &'max (), ()>)
+                                                -> $t<'a, &'min (), ()>
+                where 'max : 'min
+            {
+                v //~ ERROR mismatched types
+            }
+
+            fn not_contravariant_key<'a, 'min,'max>(v: $t<'a, &'min (), ()>)
+                                                    -> $t<'a, &'max (), ()>
+                where 'max : 'min
+            {
+                v //~ ERROR mismatched types
+            }
+
+            fn not_covariant_val<'a, 'min,'max>(v: $t<'a, (), &'max ()>)
+                                                -> $t<'a, (), &'min ()>
+                where 'max : 'min
+            {
+                v //~ ERROR mismatched types
+            }
+
+            fn not_contravariant_val<'a, 'min,'max>(v: $t<'a, (), &'min ()>)
+                                                    -> $t<'a, (), &'max ()>
+                where 'max : 'min
+            {
+                v //~ ERROR mismatched types
+            }
+        }
+    }
+}
+
+test_invariant! { foo IterMut }
+test_invariant! { bar OccupiedEntry }
+test_invariant! { baz VacantEntry }
+
+#[rustc_error]
+fn main() { }