Sizeof empty class

Question

With the code:

#include 

class A {};
class B { char x; };

int main()
{
    std::cerr << sizeof(A) << \" \" << sizeof(B) &         


        

Answer 1

There is no requirement in the C++ standard that an empty object should have one byte of memory occupied. It is purely based on the implementation.

EDIT: true, it's conforming ( ISO/IEC 14882 p.149 ):

9 Classes [class]
..
..
..
3 Complete objects and member subobjects of class type shall have nonzero size ...