Re: Integer template argument warning

Hello,

I am compiling the following code

<code>

template < unsigned int I >
class A {};

template < int I >
class B {};

template < int I >
B<-I> foo(A<I> const &)
{
 return B<-I>();
}

template < int I >
void bar(A<I> const &)
{
}

int main()
{
 A<1> a;
 foo(a); // warning here
 bar(a);
 return 0;
}

</code>

At the indicated line, Visual Studio 2009 emits the following warning:

warning C4146: unary minus operator applied to unsigned type, result
still unsigned

I don't really understand the warning. It seems to me that the problem
could be the unsigned int to int conversion of the template argument
-- once it has been converted to int, appling the unary minus operator
should be a problem. But I get this warning for foo and no warning for
bar. What is the reason behind this?

More importantly, I would like to know if there would be any work-
around to avoid the warning.

Thank you,

Paul