Nested structures

Question

The following code compiles on a C++ compiler.

#include 
int main()
{
    struct xx
    {
        int x;
        struct yy
        {
                    


        

Answer 1

Based on my brief research and the error message posted by Otto, it appears that C doesn't allow structures to be general-purpose namespace containers like C++ classes and structures are (naturally, because C doesn't even support classes). So you can't nest structure definitions in C. You would have to declare the inner structure outside of the outer structure declaration like this:

struct yy
{
        char s;
        struct xx *p;
};
struct xx
{
    int x;
    struct yy *q;
};

I see that the structures cross-reference each other. So if this is even possible in C, you may have to pre-declare the later structure with a line like:

struct xx;

(above both other declarations).