diff --git a/src/comparator.rs b/src/comparator.rs
index 56edcd4..9229351 100644
--- a/src/comparator.rs
+++ b/src/comparator.rs
@@ -53,27 +53,3 @@ pub extern "C" fn compare_callback(raw_cb: *mut c_void,
         (cb.f)(a, b)
     }
 }
-
-fn test_reverse_compare(a: &[u8], b: &[u8]) -> c_int {
-    if a < b {
-        1
-    } else if a > b {
-        -1
-    } else {
-        0
-    }
-}
-
-// #[allow(dead_code)]
-// #[test]
-// fn compare_works() {
-//    let path = "_rust_rocksdb_comparetest";
-//    let mut opts = Options::new();
-//    opts.create_if_missing(true);
-//    opts.add_comparator("test comparator", test_reverse_compare);
-//    {
-//        let db = DB::open(&opts, path).unwrap();
-//        // TODO add interesting test
-//    }
-//    assert!(DB::destroy(&opts, path).is_ok());
-// }
diff --git a/src/merge_operator.rs b/src/merge_operator.rs
index f747a8e..6d980b7 100644
--- a/src/merge_operator.rs
+++ b/src/merge_operator.rs
@@ -152,6 +152,8 @@ impl<'a> Iterator for &'a mut MergeOperands {
     }
 }
 
+#[allow(unused_variables)]
+#[allow(dead_code)]
 fn test_provided_merge(new_key: &[u8],
                        existing_val: Option<&[u8]>,
                        operands: &mut MergeOperands)
diff --git a/src/rocksdb.rs b/src/rocksdb.rs
index 5c2578b..66b5b08 100644
--- a/src/rocksdb.rs
+++ b/src/rocksdb.rs
@@ -818,6 +818,7 @@ impl ReadOptions {
     // TODO add snapshot setting here
     // TODO add snapshot wrapper structs with proper destructors;
     // that struct needs an "iterator" impl too.
+    #[allow(dead_code)]
     fn fill_cache(&mut self, v: bool) {
         unsafe {
             rocksdb_ffi::rocksdb_readoptions_set_fill_cache(self.inner, v);
@@ -854,11 +855,9 @@ impl Drop for DBVector {
 
 impl DBVector {
     pub fn from_c(val: *mut u8, val_len: size_t) -> DBVector {
-        unsafe {
-            DBVector {
-                base: val,
-                len: val_len as usize,
-            }
+        DBVector {
+            base: val,
+            len: val_len as usize,
         }
     }