How to access members through a void pointer

Question

Started by trying to write a small program to translate basic arithmetic into English, I end up building a binary tree(which is inevitably very unbalanced) to represent the

Answer 1

you could cast it:

((s*)p)->i1=1;
((s*)p)->i2=2;

I don't see any entity_flag in struct s but if you mean expr the same applies:

unsigned char flag=((expr*)vp)->entity_flag;