Fix: Add missing begin() and end() member functions to alt_string

test/src/unit-alt-string.cpp

@@ -102,6 +102,10 @@ class alt_string
         str_impl.resize(n, c);
     }
 
+	auto begin() -> std::string::iterator { return str_impl.begin(); }
+
+	auto end() -> std::string::iterator { return str_impl.end(); }
+
     template <typename op_type>
     bool operator<(const op_type& op) const
     {