Hi, everybody.

I'm trying to synthesize a function type G from another function type F with some changes on return and arg types. What I need to leave constant, are all these additional properties that are returned by components<F>::tag. I want them all as a bunch, don't really fancy querying them one by one, they sorta look contradictive or at least redundant. 

The naive approach of passing the same tag to the function_type<Seq, Tag> does not make a change - 
it leads to the same result as if default null_tag were passed. 

How do you generate a function type with the same additional properties as the given one?

 

Sample code: 
//--------------------------------------------------------------------------------------------------

typedef int (__stdcall * pF)(char);

typedef int (          * pG)(char);

 

typedef remove_pointer<pF>::type                       F;

typedef components<F>                             compsF;

 

// generate type hopefully like pF

typedef function_pointer<compsF,

                             //create tag from mask and bits

                             detail::property_tag<compsF::bits::value, compsF::mask::value>

                            >::type pfn_gen;

 

BOOST_MPL_ASSERT((is_same<pfn_gen, pG>));                   // this one passes, should fail, though

BOOST_MPL_ASSERT((is_same<pfn_gen, pF>));                   // I wish, but fails

//--------------------------------------------------------------------------------------------------

 

Thanks,