pinning revisited

[S.]

Why does that have to be a template?  Can't you deduce the size from the
typeinfo's of the variadic function?

-SC

In article <e9pmt6$20j0$1 at digitaldaemon.com>, Dave says...
>
>Jason O'Brien wrote:
>> It's not that any of us need to pin right now, but that the standard
>> puts anyone using C interop in a hard place: It's not possible to write
>> forward-compatible gc safe code.  We want to, but we can't, and so we
>> don't.  Noone is right now, and I'm afraid the more broken code we all
>> write the less likely it is a more efficient copying collector will ever
>> be worthwhile, and if it does get done all the more code we have to 
>> rewrite.
>> 
>> I have a couple of ideas, but whatever we decide on we should do it soon.
>> 
>
>The concern is valid and your ideas are good ones IMO. But for now we 
>can always get around using the GC by using malloc/free, etc.
>
>Another idea: Why not just make it easier to de/alloc using the crt and 
>place those into "auto blocks" (for now).
>
>import std.stdarg, std.c.stdlib : malloc, free;
>extern(C)
>{
>     char* strncpy(char*,char*,size_t);
>     size_t strlen(char*);
>}
>
>void main()
>{
>     size_t len = 100;
>     with(new SafeCStr(len,len))
>     {
>         const char[] str = "abcdefg...";
>         char* s = ptrs[0], d = ptrs[1];
>         strncpy(s,str,str.length);
>         strncpy(d,s,str.length);
>         printf("%s: %d\n",d,strlen(d));
>     }
>}
>
>auto class CAlloc(T)
>{
>     T*[] ptrs;
>     this(...)
>     {
>         for(size_t idx = 0; idx < _arguments.length; idx++)
>         {
>             if(_arguments[idx] != typeid(int) &&
>                _arguments[idx] != typeid(size_t))
>                 throw new Exception("wrong type of arg");
>
>             long len = va_arg!(int)(_argptr);
>
>             if(len < 0)
>                 throw new Exception("invalid allocation length");
>
>             ptrs ~= cast(T*)malloc(len * T.sizeof);
>
>             if(ptrs[idx] is null)
>                 throw new Exception("allocation failed");
>         }
>     }
>     ~this()
>     {
>         foreach(inout ptr; ptrs)
>         {
>             if(ptr)
>             {
>                 free(ptr);
>                 ptr = null;
>             }
>         }
>     }
>}
>alias CAlloc!(char) SafeCStr;