c++ sizeof() of a class with functions

Question

I have a C++ question. I wrote the following class:

class c {     int f(int x, int y){ return x; } }; 

the sizeof() of class c returns "1". I I really don't understand why it returns 1.

Trying to understand better what is going on, I added another function:

class c {      int f(int x, int y){ return x; }      int g(int x, int y){ return x; } }; 

Now the following really got me confused! sizeof(c) is still 1 (!?!?!?!). So I guess that functions doesn't change the size of the class, but why??? and why does the size is 1 ? And is it compiler specific ?

Thanks! :-)

Answer 1

The class contains no data members, so it's empty. The standard demands that every class have at least size 1, so that's what you get. (Member functions aren't physically "inside" a class, they're really just free functions with a hidden argument and a namespace and access control.)

Answer 2

It's size is of 1, because it can not be 0, otherwise two objects of this type wouldn't be addressable (couldn't differentiate their addresses)