Will this trick work in C?

Question

I want to add a field to a structure in C. So for example I have the following structure.

struct A
{
 some_type x;
 some_type y;
}

I declare a

Answer 1

No it won't work. It would work if you change it a bit:

struct A
{
 some_type x;
 some_type y;
}; /* <- note semicolon here */


struct B
{
 struct A a;
 some_type z;
}; /* ... and here */


int some_function(struct A *a ); /* ... and here ... */


struct B *b;
......
struct A *a = (struct A*)b;
some_function( a );