Function mi_expand 

pub unsafe extern "C" fn mi_expand(
    p: *mut c_void,
    newsize: usize,
) -> *mut c_void

Try to re-allocate memory to newsize bytes in place.

Returns null on out-of-memory or if the memory could not be expanded in place. On success, returns the same pointer as p.

If newsize is larger than the original size allocated for p, the bytes after size are uninitialized.

If null is returned, the original pointer is not freed.

Note: Conceptually, this is a realloc-like which returns null if it would be forced to reallocate memory and copy. In practice it’s equivalent testing against mi_usable_size.