Simplify write/read code

include/storage/io.hpp

@@ -284,6 +284,8 @@ class FileWriter
         }
     }
 
+    template <typename T> void WriteFrom(const std::vector<T> &src) { WriteFrom(src.data(), src.size()); }
+
     template <typename T> void WriteFrom(const T &src) { WriteFrom(&src, 1); }
 
     template <typename T> void WriteOne(const T tmp) { WriteFrom(tmp); }