No. The problem is that you have to have that metadata there, where ever it is that you want to point. What if it's not there? Oh yeah, doesn't work. It's j

No. The problem is that you have to have that metadata there, where ever it is that you want to point. What if it's not there? Oh yeah, doesn't work. It's just a normal pointer, pointing to an array and header. If I pick up some library (or system call interface..), and it uses this structure struct foo { struct bar a; char b[64]; }; The metadata field that cello wants is not there. I cannot use cello's "fat pointers" because they are not fat pointers at all. I would have to modify the struct to have array-with-length-header (which is what cello calls a fat pointer.. talk about confusing pointers and arrays!) , which might be impossible if it's someone else's binary interface that I am using. If I had actual fat pointers, then the size would be simply passed together with the pointer and I wouldn't have to have modify structures to accommodate an extra field. Of course, I can't pass these pointers to functions that expect normal pointers, but it wouldn't make sense to do that anyway, and if implemented right, doing that would require me to misdeclare a function. You would pass normal pointers to old C code that expects and deals with normal pointers.