Can there be a C++ type that takes 0 bytes

Question

I\'m trying to declare a C++ variable that takes up zero bytes. Its in a union, and I started with the type as int[0]. I don\'t know if that is actually zero bytes (although

Answer 1

The typedef is misspelled:

typedef int nullType[0];

As others have pointed out, you cannot have an object of size 0; However, compilers can (and frequently do) provide the Empty Base Class optimization.

• http://en.wikibooks.org/wiki/More_C%2B%2B_Idioms/Empty_Base_Optimization
• http://www.cantrip.org/emptyopt.html ("empty member" optimization)