[Boost-users] Re: Question

From: Eric Niebler (eric_at_[hidden])
Date: 2005-05-13 13:25:51

Please don't top post ... reordered.

> 
> VC6 is pretty strange, I agree. In particular, it doesn't handle 
> functions with non-type template parameters well. The following code 
> should demonstrate the problem. (Hopefully I'm remembering the problem 
> correctly -- I don't have VC6 installed on this machine.)
> 
> template<int I> void foo() { std::cout << I << '\n'; }
> 
> int main() {
>    foo<1>();
>    foo<2>();
>    return 0;
> }
> 
> If you must use VC6, avoid non-type template parameters for function 
> templates.
> 
> 

Sliwa, Przemyslaw (London) wrote:
 > This returns in both cases the same value.
 > Is there a way around this problem at all?
 >
 > Thanks
 >
 > Pshemek
 >

Try using integer wrappers. The MPL ones should do the trick:

template<typename Int> void foo()
   { std::cout << Int::value << '\n'; }

int main() {
   foo<mpl::int_<1> >();
   foo<mpl::int_<2> >();
   return 0;
}

The original problem was using bools as a non-type template parameter, 
so the fix would be to use mpl::true_ and mpl::false_.

-- 
Eric Niebler
Boost Consulting
www.boost-consulting.com