[libstdc++ PATCH] TR1 'function' and 'mem_fn' support

[Chris Jefferson]

Benjamin Kosnik wrote:

>>The attached patch adds support for std::tr1::function and std::tr1::mem_fn to 
>>libstdc++. The good news is that it implements the complete specification and 
>>passes all of the existing libstdc++ tests (plus the two new tests) on x86 
>>Linux. The bad news is that it only passes when using my (unreviewed) patch 
>>for making member pointers work properly with function types, posted here:
>>
>> http://gcc.gnu.org/ml/gcc-patches/2005-01/msg01627.html
>>    
>>
>
>Let's try to get this reviewed. Jason? You'd indicated a willingness to
>prioritize TR1 work in Redmond. What do you think of this patch, and is
>this something we can get into 4.0?
>
>  
>
>>It is possible to work around the bugs fixed by that patch, but it's very, 
>>very ugly and will require a lot of new code. As it is, any implementation of 
>>these facilities requires a huge amount of repetition; in this case, I've 
>>chosen to repeatedly include a header file, using macros to generate 
>>different code each time. 
>>    
>>
>
>Yes. I saw that.
>
>:(
>
>I'm trying to think of a better way to do this, but cannot at the
>moment. There's no way to avoid this kind of insanity without variadic
>templates, or something like that. 
>
>Bummer.
>
>I'm sure that if somebody comes up
>with a great idea to do this without the macro hacks at some point in
>the future, or with approved template extensions, we can discuss it
>then. 
>  
>
I'm happy to adapt my tuple generation program to generate this header, 
which would have the advantage it would remove of 10 on the maximum 
size. Of course this leads to other problems which I'm not positive how 
to fix.... but it seems like it's not impossible someone might hit the 
10-parameter (I've seen functions with more, although not in very nice code)

Chris