Re: [Boost-users] bosst::bind problem

From: Jasper, Alexander (alexander.jasper_at_[hidden])
Date: 2005-07-28 01:52:54

Hi Oleg!

your function Handler::Test2 takes 2 arguments + this. But your code passes 3 arguments + this to the function  boost::bind(&Handler::Test2, _1, _2, a, b)). If I'm not completely mistaken that cannot work. What did you expect the _2 to be in this case?. Using the _2 also implies that the resulting function of the bind expects 2 arguments. That is you cannot simply use it with for_each in that kind of way. This supplies only one parameter.

kind regards

Alex

> -----Ursprüngliche Nachricht-----
> Von: boost-users-bounces_at_[hidden]
> [mailto:boost-users-bounces_at_[hidden]]Im Auftrag von 
> Oleg Smolsky
> Gesendet: Donnerstag, 28. Juli 2005 03:22
> An: boost-users_at_[hidden]
> Betreff: [Boost-users] bosst::bind problem
> 
> 
> Hi all,
> 
> I've just started using boost::bind and found the following problem:
> 
> class Handler
> {
> public:
>     bool Test1(std::string sComponent);
>     bool Test2(std::string sComponent, std::string sAddress);
> };
> 
> void Test()
> {
>     std::vector<Handler>    v;
> 
>     // This compiles
>     std::string             a, b;
>     std::for_each(v.begin(), v.end(),
>                   boost::bind(&Handler::Test1, _1, a));
> 
>     // This doesn't compile
>     //std::for_each(v.begin(), v.end(),
>     //              boost::bind(&Handler::Test2, _1, _2, a, b));
> }
> 
> Environment: boost 1.32, VC8, WinXP.
> 
> Any ideas?
> 
> Thanks,
> Oleg.
> 
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