View Compilation Error

0_0_32650637_15343.cpp: In function 'int main()':
0_0_32650637_15343.cpp:30:16: error: invalid use of member (did you forget the '&' ?)
         length += word.size;
                ^
0_0_32650637_15343.cpp:30:16: error:   in evaluation of 'operator+=(int, <unresolved overloaded function type>)'