Nested structs and struct.pack

[ken_ar at my-deja.com]

Hi!

I'm having problems with nested C structs and the
struct module. The size of the structs are
different for Python and C. The following
describes the problem:

// C
#include <stdio.h>

struct a
{
        long a;
};

typedef struct a A;

struct b
{
        A a;
        char c;
};

typedef struct b B;

struct c
{
        B b;
        char c;
};

typedef struct c C;

int main(int argc, char* argv[])
{
        printf("Type sizes\n");
        printf("A    : %u\n", sizeof(A));
        printf("B    : %u\n", sizeof(B));
        printf("C    : %u\n", sizeof(C));
}
// end

Here the size of C is 12.

# Python

import struct
struct.calcsize("lcc")
# end

Here the size is 8.

I've probably misunderstood how the compiler lays
out nested structs. But is there any way to tell
the struct module that I have nested structs so
that the C compiler and Python produce the same
result ?

With regards,
-Ken.


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