[boost] Re: [interfaces] Hand written interfaces

4 Mar 2005


      Jonathan Turkanis wrote:
...
Is the following definition of IBar so complex that it would be
pointless to offer it as an alternative?
template< typename Derived,
             typename Base,
             typename Flags >
   struct ibar_impl {
        struct type : Base {
            struct interface_metadata : metadata_base<Derived, Base,
                Flags> { const char* names = { "foo", "foo" };
                typedef mpl::vector<
                            void(const char*),
                            int(int, int)
                        > signatures;
            };
            void foo(const char* name)
            {
                return invoker<interface_metadata, 1>::execute(this,
            name); }
int foo(int n, int m)
            {
                return invoker<interface_metadata, 2>::execute(this,
            int, int); }
        };
   };
I simplified it a bit:

   template< typename Derived,
             typename Base,
             typename Flags >
   struct ibar_impl {
        struct type : Base {
            struct interface_metadata : metadata_base<Derived, Base, Flags> {
                const char* names = { "foo", "foo" };
                typedef mpl::vector<
                            void(const char*),
                            int(int, int)
                        > signatures;
            };
            void foo(const char* name) { return execute<1>(this, name); }
            int foo(int n, int m) { return execute<2>(this, int, int); }
        };
   };

   typedef interface< ibar_impl<_, _, _> > IBar;

Jonathan