Have default hash function returns a digest

Author: kamikat

src/bf/hash.cc

@@ -9,7 +9,7 @@ default_hash_function::default_hash_function(size_t seed)
 {
 }
 
-size_t default_hash_function::operator()(object const& o) const
+digest default_hash_function::operator()(object const& o) const
 {
   // FIXME: fall back to a generic universal hash function (e.g., HMAC/MD5) for
   // too large objects.

src/bf/hash.h

@@ -23,10 +23,10 @@ class default_hash_function
 
   default_hash_function(size_t seed);
 
-  size_t operator()(object const& o) const;
+  digest operator()(object const& o) const;
 
 private:
-  h3<size_t, max_obj_size> h3_;
+  h3<digest, max_obj_size> h3_;
 };
 
 /// A hasher which hashes an object *k* times.