What do you mean "reassign"?

You can't reassign the length variable since it's marked `const`. You should see something like "warning: assignment discards `const` qualifier from pointer target type" if you pass it to `realloc`, which tells you that you're breaking consistency (I guess this might be UB). You could write `vrealloc` to allow resizing such structs, which would probably be called like:

    my_obj *tmp = vrealloc(obj, sizeof(obj), sizeof(obj->text), obj->n, newsize);

What would you do with the old text? Delete it?

Could you please be more specific about what you're trying to say? I have no idea what your actual objection is.