use assert_eq! in test and return vec from unsafe

src/db.rs

@@ -671,18 +671,17 @@ impl DB {
         };
 
         let mut length = 0;
-        let vec;
 
         unsafe {
             let ptr = ffi_try!(ffi::rocksdb_list_column_families(opts.inner,
                                                                  cpath.as_ptr() as *const _,
                                                                  &mut length));
 
-            vec = Vec::from_raw_parts(ptr, length, length).iter().map(|&ptr| {
+            let vec = Vec::from_raw_parts(ptr, length, length).iter().map(|&ptr| {
                 CString::from_raw(ptr).into_string().unwrap()
             }).collect();
+            Ok(vec)
         }
-        Ok(vec)
     }
 
 

tests/test_column_family.rs

@@ -68,7 +68,7 @@ pub fn test_column_family() {
         let opts = Options::default();
         let vec = DB::list_cf(&opts, path);
         match vec {
-            Ok(vec) => println!("list cf: {:?}", vec),
+            Ok(vec) => assert_eq!(vec, vec!["default", "cf1"]),
             Err(e) => panic!("failed to drop column family: {}", e),
         }
     }