Re: [Boost-users] fusion::result_of::transform<Seq1, Seq2, F> -- argument dependent result type

e r wrote:

Steven Watanabe wrote:

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AMDG

e r wrote:

...

// probably not what result_of::transform expects, based on compile // errors (below) template struct result{ typedef typename Metafun::type type; };

Fusion uses Boost.ResultOf. http://www.boost.org/doc/libs/1_36_0/libs/utility/utility.htm#result_of

In Christ, Steven Watanabe

Thanks. I read the link above before posting as well as the proposal:

//example from proposal. struct square_ { template<typename T> struct result { typedef T type; }

template<typename T> T operator()(T& x) const { return x*x; } };

but I'm not qualified enough to deduce the right answer in my case. i thought id would be like this:

template<typename Arg1> struct fun{ template struct result{ typedef typename Metafun::type type; };

template typename Metafun::type operator()(const Metafun& meta,const Arg2& arg2)const{ typedef typename Metafun::type result_type; return result_type(args,arg2); } };

but apparently it's not correct. I guess I can't fully make sense of F::result::type. any hint here would be really helpful.

thanks!

I may have made a little bit of progress here... struct fun{ template<typename Signature> struct result; template<typename A> struct result{ typedef A type; }; template<typename A> A operator()(const A& a)const{ return A(); }; }; typedef boost::result_of::type result_type; BOOST_MPL_ASSERT( ( mpl::is_same< result_type, my > ) );