structure

Can I inherit a structure in C? If yes, how? Daniel Earwicker The closest you can get is the fairly common idiom: typedef struct { // base members } Base; typedef struct { Base base; // derived members } Derived; As Derived starts with a copy of Base , you can do this: Base *b = (Base *)d; Where d is an instance of Derived . So they are kind of polymorphic. But having virtual methods is another challenge - to do that, you'd need to have the equivalent of a vtable pointer in Base , containing function pointers to functions that accept Base as their first argument (which you could name this ).

I'm working on a mailbox project, and I have these two structures: struct mmbox_mail struct mmbox_mail { char *sender, *recipient; char *obj, *date; char flags; size_t size; }; and mail_t typedef struct{ struct mmbox_mail info; void *body; void *next; } mail_t; I cannot modify the structures' fields, because I need variable data (for this purpose I used char* instead of char[]). Each mail_t structure is a mail. I need to save every mail of a user in a file, that could be binary or text file (but I think it's better with a binary file, because I have the void* body that is difficult to save in

I want to combine two structures with differing fields names. For example, starting with: A.field1 = 1; A.field2 = 'a'; B.field3 = 2; B.field4 = 'b'; I would like to have: C.field1 = 1; C.field2 = 'a'; C.field3 = 2; C.field4 = 'b'; Is there a more efficient way than using "fieldnames" and a for loop? EDIT: Let's assume that in the case of field name conflicts we give preference to A . Without collisions, you can do M = [fieldnames(A)' fieldnames(B)'; struct2cell(A)' struct2cell(B)']; C=struct(M{:}); And this is reasonably efficient. However, struct errors on duplicate fieldnames, and pre