Super- and sub-classing C structs

base_struct.c

// A "base struct" from which other "substructs" will inherit
typedef struct {
    int value;
} base_struct;

gist.c

sub_struct s;
s.value2 = 13;

// Cast a pointer to the sub_struct (using the address-of operator) to a pointer,
// pointing to the base_struct type to access its members without having to reference the base_struct:
base_struct *b;
b = ((base_struct*) &s);
b->value = 43;

// Alternatives:
// (base_struct*) &s)->value = 37;
// s.super.value = 37;

sub_struct.c

// A "substruct" derived from its "superstruct"
typedef struct {
    base_struct super;
    int value2;
} sub_struct;