;compile ```c struct a{ int l; int m[]; },; union{ struct a a; int q[4]; },b={3},; b.a.m[0]=1; b.a.m[1]=2; b.a.m[2]=3;```
how would I tweak this to have some ```c union { struct a a; char dummy[s]; }, ``` where `s` is of the kind of what I wrote above in `ctx *t = malloc(sizeof(*t) + element_count * sizeof(*(t->buffer)));` ?