Re: Help with returns_ref_to_const meta-function

on Thu Nov 08 2007, Edd <edd-AT-nunswithguns.net> wrote:


                             ^^^
This will give you trouble when non-PODs are returned.

Try the code below (untested).

   class Tester
   {
         typedef char val;
         typedef char (&ref_to_nonconst)[2];
         typedef char (&ref_to_const)[3];

         static Arg& testval;

         template<class R>
         static ref_to_const
         testfunc(R&, int, typename enableifnonconst<R>::type = 0);

         template<class R>
         static ref_to_nonconst
         testfunc(R&, int, typename enableifconst<R>::type = 0);

         template <class R>
         static val testfunc(R, ...);

   public:
         static const size_t value = sizeof(testfunc(f(testval),0));

   };

--
Dave Abrahams
Boost Consulting
http://www.boost-consulting.com

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