Re: [boost] Variadic Templates Redux

From: Jeff Garland (jeff_at_[hidden])
Date: 2006-09-26 18:04:29

Doug Gregor wrote:
> A while ago I announced the availability of an implementation of  
> "variadic templates" for GCC. Variadic templates eliminate a huge  
> amount of redundancy in several Boost libraries (including some that  
> have gone into TR1), such as tuples, function, bind, mem_fn, and MPL.  
> I have now completed the compiler (everything I've thought to try  
> works) and completely reimplemented TR1's <tuple> and <functional>  
> headers using variadic templates. The resulting code is much smaller,  
> clean, and compiles significantly faster that the previous versions.  
> Compiler binaries and sources, both including the implementation of  
> TR1, are available here:
> 
> 	http://www.osl.iu.edu/~dgregor/cpp/variadic-templates.html
> 
> I think variadic templates are a big step forward for C++ libraries  
> that deal with function objects, forwarding, and type-lists. If  
> you're interested, please read the documentation, hack some code with  
> the compiler, and tell your local C++ committee representative to  
> vote for variadic templates in C++0x :)

FWIW, I'll add a quick word of support for this feature.  I ran into this very 
issue with my implementation of the 'super_string' class where I wanted to 
have an unlimited number of template function parameters for functions like 
type conversion and and formatted output.  It's painful to write/test all the 
different overloadings to an 'arbitrary level'. Honestly, I punted and didn't 
write as many overloads as I should have...luckily no one has complained - yet 
;-) I looked at your spec when you first posted and I believe it would solve 
my issue quite nicely.

Thanks for doing this.

Jeff