Re: [boost] Simulating partial ordering (was Re: Boost.Format final submission)

From: David Abrahams (david.abrahams_at_[hidden])
Date: 2002-02-23 11:50:15

----- Original Message -----
From: "Aleksey Gurtovoy" <alexy_at_[hidden]>

>     #include <iostream>
>
>     template< typename T > struct A {};
>
>     namespace aux {
>     template< typename T >
>     struct foo_impl
>     {
>         template< typename U >
>         static void foo(A<U> const&, long)
>         {
>             std::cout << "foo(A<U> const&)\n";
>         }
>
>         static void foo(T const&, int)
>         {
>             std::cout << "foo(T const&)\n";
>         }
>     };
>     }
>
>     template< typename T >
>     void foo(T const& t)
>     {
>         aux::foo_impl<T>::foo(t, 1L);
>     }
>
>     int main()
>     {
>         foo(int());
>         foo(A<int>());
>         return 0;
>     }
>
> That's more, I belive that the technique allows you to simulate partial
> ordering of any number of overloaded function templates, not just 2 of
them.

Whoa, that's tricky! How do you extend it to more overloads?