Hello #cpp / #cplusplus Fediverse,

[riley@toot.cat]

@oblomov Never mind:

#include <stdio.h>                                           

struct par1 {                                                
  int par1a;                                                 
  par1() : par1a(1) {}                                       
};                                                           

struct par2 {                                                
  int par2a;                                                 
  par2() : par2a(2) {}                                       
};                                                           

struct child : par1, par2 {                                  
  int chfield3;                                              
  child() : chfield3(3) {}                                   
};                                                           

int main () {                                                
  child ch;                                                  
  printf("ch.par1a = %i, ch.par2a = %i, ch.chfield3 = %i\n", 
      ch.par1a, ch.par2a, ch.chfield3);                      
  printf("&ch = %p, (par1 *)&ch = %p, (par2 *)&ch = %p\n",   
      &ch, (par1 *)&ch, (par2 *)&ch);                        
  return 0;                                                  
}                           

I might be able to make this work. Pondering.

@lesley

[oblomov@sociale.network]

@riley

sure: https://godbolt.org/z/YvYa9b7jb

You do lose the POD property on foo though. Depending on your needs this may or may not be important.

@lesley

[riley@toot.cat]

@ananas Well, if I have to autogenerate, I could do this instead:

template <class T>
void work_on_paydirt (T *ambi_object) {
  struct bar *object = ambi_object->gimme_bar();
  printf("Teh paydirt is %i\n", object->paydirt);
}

Slightly less bulky, but it looks ugly.

[riley@toot.cat]

@oblomov Where does the PODness go?

@lesley

[oblomov@sociale.network]

@riley @lesley well, you can't share a type with inheritance (multiple or not) with C, so it's Plain Old Data (although you CAN design an aliasing C type for that if you need it)