Add a test to ensure BitFlags implements Hash

Author: meithecatte

test_suite/common.rs

@@ -1,4 +1,4 @@
-#[derive(BitFlags, Copy, Clone, Debug, PartialEq)]
+#[derive(BitFlags, Copy, Clone, Debug, PartialEq, Eq, Hash)]
 #[repr(u8)]
 enum Test {
     A = 1 << 0,

test_suite/tests/requires_std.rs

@@ -92,3 +92,11 @@ fn debug_generic() {
 
     let _ = format!("{:?}", Debug(BitFlags::<Test>::all()));
 }
+
+#[test]
+fn works_in_hashmap() {
+    // Assert that BitFlags<T> implements Hash.
+
+    use std::collections::HashMap;
+    let _map: HashMap<BitFlags<Test>, u8> = HashMap::new();
+}