char ***argc problems.

[Andrew]

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.

Thanks for the help

-Andrew