TITLE: specializing template functions in namespace std

(Source: editted private correspondence, 2 Feb 2001)

AUTHOR: Jon Kalb [Kalb@LibertySoft.com]

[snip]

It turns out that this is legal:

namespace std
{
     template<> void swap(UserClass&a, UserClass&b) {...}
}

But this is not:

namespace std
{
     void swap(UserClass&a, UserClass&b) {...}
}

The rule in this case is that you can *specialize* but not 
overload a template function. So [the above] is out because 
it's not a template.

namespace std
{
    template<typename T> void swap(UserTemplateClass<T>&a, 
        UserTemplateClass<T>&b) {...}
}

And [the above is not legal] because it would require partial 
specialization. Which is only supported for template classes, 
not template functions.

Something's got to give, because clearly the UserTemplateClass 
example has to have a solution. So we are either going to get 
overloading (as well as specialization) of standard template 
functions or we are going to get partial specialization of function 
templates.



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