Re: [Boost-users] [MPL/Fusion?]Call a 0-args template function on members of a sequence

24 Aug 2006

      David Abrahams wrote:
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struct call_f
  {
     template <class Wrapper>
     void operator()(Wrapper)
Sorry, it's missing a "const" right here--^^^^
     {
         f<typename Wrapper::type>();
     }
  };
mpl::for_each >(call_f());
I didn't find this in the docs. Is it meant to be there?
The specific answer to your specific problem?  No.  Oh yeah, for_each
wasn't documented in 1.33.1... and apparently it isn't documented in
the CVS head either (still?  Aleksey?)
Yep, I was referring to mpl::for_each in general.
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Unfortunately, that didn't quite work for me, anyway. A requirement
of for_each (according to my MSVC 8 diagnostics) is that each type
in the sequence must be default constructible.
In the case above, only mpl::identity<T> needs to be
default-constructible for each type in the list... or that was my
intention Ach!  My mistake...
template <class T> 
    struct make_identity { typedef mpl::identity<T> type; };
mpl::for_each >(call_f());
should work.
Like a charm! Many thanks!

Kind Regards,

Edd

Re: [Boost-users] [MPL/Fusion?]Call a 0-args template function on members of a sequence

Edd Dawson