Re: bind, template functions, and the linker

From: Gennadiy E. Rozental (rogeeff_at_[hidden])
Date: 2001-10-22 13:21:37

What compiler ar you using? If it MSVC it's appears to be known issue 
and usin gtemporary could help.

--- In boost_at_y..., brownell_at_a... wrote:
> I don't think this is a problem with bind, but more of a C++ issue, 
> so my apologies if this is a bit off topic.  I am passing a 
template 
> function to bind, and the resulting "bound" function is used as the 
> UnaryFunction in std::for_each.  When I compile this application, 
> everything works as expected, but when the linker does its thing, 
it 
> can't find the template function.  If I make a dummy call to the 
> template function, the function code is created and the linker is 
> happy.  Is there a way I can make this all work without the dummy 
> call to the template function?  I have a code example illustrating 
> the problem below.
> 
> Thanks in advance for your help!
> Dave
> 
> #include<vector>
> #include<algorithm>
> 
> #include "boost\bind.hpp"
> 
> template<class T>
> bool TemplateFunction(T &t)
> {
>     t = 2;
>     return(true);
> }
> 
> int main(void)
> {
>     std::vector<unsigned long>          v;
> 
>     v.resize(10);
> 
>     //If this code segment is commented, it will not link.  
Uncomment
>     //  to resolve the link error
>     /*{
>         unsigned long       ulTemp;
> 
>         TemplateFunction(ulTemp);
>     }*/
> 
    bool (*temp)( unsigned long& ) = &TemplateFunction<unsigned long>;

     std::for_each(v.begin(), v.end(), boost::bind(temp, _1));
     return(1);
> }