Short answer: No. The compiler picks a size it feels appropriate (VC++ always picks 4 bytes, AFIK).
If you could change the code you could use
enum fruit : char{ apple, banana, orange };
This is a non-standard extension to C++03 that Visual C++ supports.
I am a little curious what scenario permits you to recompile code in a way that changes the sizes of variables and layout of structures but does not permit you to modify the source code. I really cannot think of a case that this would be successful
to achieve anything useful, other than to cause random crashes if you try to link that code to something else that expected the old sizes.
