char ***argc problems.

[Timon Gehr]

On 08/12/2012 11:38 PM, Andrew wrote:
> On Sunday, 12 August 2012 at 20:57:34 UTC, Timon Gehr wrote:
>> On 08/12/2012 10:33 PM, Andrew wrote:
>>> I'm attempting to create a wrapper for MPI, however, MPI_Init
>>> wants to read the arguments for main():
>>>
>>> MPI_Init(int *argv, char ***argc);
>>>
>>> How do I get this last level of pointer reference?
>>>
>>> So far, I have:
>>>
>>> void main (string[] args)
>>> {
>>>    auto argarr = new char*[args.length];
>>>    foreach(i, a; args)
>>>    argarr[i] = (a.dup ~ '\0').ptr;
>>>
>>>    int argc = to!(int)(argarr.length);
>>>    MPI_Init(&argc, argarr.ptr);
>>> }
>>>
>>> Any ideas?
>>>
>>> -Andrew
>>
>> Maybe like this?
>>
>> import std.algorithm, std.array, std.conv;
>> void main(string[] args){
>>     auto argarr = args.map!(a=>(a ~ '\0').ptr).array;
>>
>>     int argc = to!(int)(argarr.length);
>>     auto argv = argarr.ptr;
>>
>>     MPI_Init(&argc, &argv);
>>
>>     args = argv[0..argc].map!(to!string).array;
>>
>>     // ...
>> }
>
> I don't know why I didn't think of this:
>
> auto argv = argarr.ptr;
>
> Which fixed it.
>
> Unfortunately, using args.map! doesn't work, because it returns
> an immutable, which MPI_Init can't take.
>

oops.
auto argarr = args.map!(a=>(a.dup ~ '\0').ptr).array;

> Thanks for the help
>
> -Andrew
>