Address of a variable: Difference between revisions

julia> unsafe_pointer_to_objref(ptr)

3</lang> The latter is "unsafe" because it only works if <code>ptr</code> refers to a valid heap-allocated "boxed" Julia object, which can only be safely allocated by Julia itself.

 

Another common use of pointers is for arrays of values, which are typically passed in low-level C-like libraries via pointers to contiguous sets of values in memory. This is accomplished in Julia by the <code>pointer(A)</code> function, which returns a pointer to the data stored in a high-level Julia array <code>A</code>. Given a pointer <code>p</code> to values of a given type, the <code>i</code>-th value (numbered starting at 1 for the value pointed to by <code>p</code>) can be read or written by the low-level <code>unsafe_load(p, i)</code> and <code>unsafe_store!(p, val, i)</code> functions, or it can be converted back to a high-level Julia array type by the <code>pointer_to_array(p, dimensions)</code> function:<lang julia>julia> A = [1, 2.3, 4]