Hmm.

I can do this:

void variadic(T...)(T args){}
variadic(1, 2, 3);

This:

void returnType(T)(T delegate() dg){}

returnType(delegate int(){ return 0; });

Even this:

void returnAndArg(T, U)(T delegate(U) dg){}
returnAndArg(delegate int(bool b){ return 0; });

But not:

void returnAndArgs(T, U...)(T delegate(U) dg){}
returnAndArgs(delegate int(bool b){ return 0; });

!

One can dream, no?

Is there maybe some other way to get at the parameter types of a function as a tuple, using variadic magic?

Jarrett Billingsley wrote:
> Is there maybe some other way to get at the parameter types of a function as a tuple, using variadic magic? 

How about this stuff: http://www.dsource.org/projects/pyd/browser/trunk/infrastructure/meta ?

"Tom S" <h3r3tic@remove.mat.uni.torun.pl> wrote in message news:eigch3$ilf$1@digitaldaemon.com...
> Jarrett Billingsley wrote:
>> Is there maybe some other way to get at the parameter types of a function as a tuple, using variadic magic?
>
> How about this stuff: http://www.dsource.org/projects/pyd/browser/trunk/infrastructure/meta ?

But that's basically using my third example, i.e.

void returnAndArg(T, U)(T delegate(U) dg){}
returnAndArg(delegate int(bool b){ return 0; });

But with many specializations of the template, one for each number of params.  The point of using variadic templates is removing the need to manually create a specialization for each number of things you want in the typelist.  With the automatic tuple deduction that I wish existed, the FuncMeta.d module would become about 80 lines of code, and it would be able to support any number of arguments.

Jarrett Billingsley wrote:
> "Tom S" <h3r3tic@remove.mat.uni.torun.pl> wrote in message news:eigch3$ilf$1@digitaldaemon.com...
>> Jarrett Billingsley wrote:
>>> Is there maybe some other way to get at the parameter types of a function as a tuple, using variadic magic?
>> How about this stuff: http://www.dsource.org/projects/pyd/browser/trunk/infrastructure/meta ?
> 
> But that's basically using my third example, i.e.
> 
> void returnAndArg(T, U)(T delegate(U) dg){}
> returnAndArg(delegate int(bool b){ return 0; });
> 
> But with many specializations of the template, one for each number of params.  The point of using variadic templates is removing the need to manually create a specialization for each number of things you want in the typelist.  With the automatic tuple deduction that I wish existed, the FuncMeta.d module would become about 80 lines of code, and it would be able to support any number of arguments. 
> 
> 

This was approximately the first thing I tried doing with variadic templates. I was very saddened to see that it doesn't work.

-- 
Kirk McDonald
Pyd: Wrapping Python with D
http://pyd.dsource.org

Kirk McDonald wrote:
> This was approximately the first thing I tried doing with variadic templates. I was very saddened to see that it doesn't work.

I agree, and I'll break out the hammer & tongs and see if I can make it work.