converting D's string to use with C API with unicode

[Jack]

I totally forget to malloc() the strings and array. I don't do C 
has been a while and totally forget this, thank you so much guys 
for your answer.

my code now look like this, still there's a memory corrupt. Could 
anyone help point out where is it?

>struct ProcessResult
>{
>	string[] output;
>	bool ok;
>
>	C_ProcessResult* toCResult()
>	{
>		import core.stdc.stdlib : malloc, free;
>		import core.stdc.string : memcpy;
>		import core.exception : onOutOfMemoryError;
>		import std.encoding : transcode;

>		auto mem = malloc(C_ProcessResult.sizeof);
>		if(!mem) {
>			onOutOfMemoryError();
>		}
>		auto r = cast(C_ProcessResult*) mem;
>		r.ok = this.ok;
>		r.outputLength = cast(int) output.length;
>		r.output = cast(wchar**) malloc((wchar*).sizeof * 
>output.length);
>		if(!r.output) {
>			onOutOfMemoryError();
>		}
>		foreach(i; 0..output.length) {
>			wstring ws;
>			transcode(output[i], ws);
>			auto s = malloc(ws.length + 1);
>			if(!s) { 				onOutOfMemoryError();
>			}
>			memcpy(s, ws.ptr, ws.length);
>			r.output[i] = cast(wchar*)s;
>		}
>		return r;
>	}
>}