/in/ex5.cpp: In member function 'void bookInventory::removeBook(int)':
/in/ex5.cpp:65:11: error: suggest parentheses around assignment used as truth value [-Werror=parentheses]
     if(ID = int(size)){
        ~~~^~~~~~~~~~~
cc1plus: all warnings being treated as errors
/in/compile/Makefile:26: recipe for target 'ex5.o' failed
make: *** [ex5.o] Error 1