If you want a C-ABI compatible struct, you can do this:
type ITree
isLeaf::Cint # there is no "bool" in C, so what is this?
n::Cint
ptr::Ptr{Void}
end
Then you can just convert(Ptr{Int}, t.ptr) or convert(Ptr{ITree}, t.ptr)
depending on t.isLeaf.
On Sat, Jun 27, 2015 at 5:17 PM, Stefan Karpinski <[email protected]>
wrote:
> I interpreted the question as "how do I do this kind of thing in Julia"
> rather than how do I make a binary-compatible structure (clearly I'm
> failing at that).
>
> On Sat, Jun 27, 2015 at 4:46 PM, Keno Fischer <
> [email protected]> wrote:
>
>> That struct is not ABI compatible to the given struct, which I believe
>> was the original question. To get an ABI compatible version, you'll have to
>> use the same types as the C version. Since unions aren't supported in an
>> ABI compatible way, this generally does not work for such structs, but in
>> this case you can use a single pointer.
>>
>> On Sat, Jun 27, 2015 at 4:42 PM, Stefan Karpinski <[email protected]>
>> wrote:
>>
>>> type ITree
>>> n::Int
>>> children::Union(Vector{Int},Vector{ITree})
>>> end
>>>
>>> julia> t = ITree(123, [1,2,3])
>>> ITree(123,[1,2,3])
>>>
>>> julia> ITree(234, [t])
>>> ITree(234,[ITree(123,[1,2,3])])
>>>
>>> On Sat, Jun 27, 2015 at 10:50 AM, <[email protected]> wrote:
>>>
>>>> I am new to Julia with mostly C and some MATLAB background. Julia
>>>> seems to provide an easy way to write C like code with MATLAB ease! To get
>>>> started, I am trying understand C interface. Is it be possible to create a
>>>> Julia type for the following struct?
>>>>
>>>> typedef struct itree {
>>>> bool isLeaf;
>>>> int n; //number of elements
>>>> union {
>>>> int *i; //(isLeaf == 1): pointer to int array
>>>> struct itree **s; //(isLeaf == 0): pointer to itree array
>>>> };
>>>> } itree;
>>>>
>>>> It seems, that the size of the pointer should be the same. So,
>>>> anonymous union should be possible.
>>>> I would appreciate any suggestions.
>>>>
>>>> Thanks,
>>>> ~Sue
>>>>
>>>>
>>>
>>
>
