Re: [Boost-users] [phoenix][units] make boost.phoenix play well with boost.units

On Jun 4, 5:55 pm, alfC wrote: So, I have to implement this kind of macro sorcery to bridge Boost.Units and Boost.Phoenix. Not sure if I will find another bump in the road:

namespace boost{ namespace phoenix{ using namespace boost::units; #define RESULT_OF_GEN( PhoenixnamE, UnitsnamE, RefQ1, RefQ2 ) \        template \        struct result_of_##PhoenixnamE RefQ1, quantity RefQ2>{ \                typedef typename UnitsnamE##_typeof_helper&,quantity&

...

::type type; \        };        RESULT_OF_GEN(multiplies, multiply, &,  )        RESULT_OF_GEN(multiplies, multiply, &, &)        RESULT_OF_GEN(multiplies, multiply,  ,  )        RESULT_OF_GEN(multiplies, multiply,  , &)        RESULT_OF_GEN(divides   , divide  , &,  )        RESULT_OF_GEN(divides   , divide  , &, &)        RESULT_OF_GEN(divides   , divide  ,  ,  )        RESULT_OF_GEN(divides   , divide  ,  , &) #undef RESULT_OF_GEN }}

On top of what is above, I had to add the code below in order to be able to use Phoenix in this context: using namespace boost::units; using namespace boost::phoenix; using namespace boost::phoenix::arg_names; ... boost::functionsi::area(quantitysi::length)> f = arg1 * si::meter; cout << f(4.*si::meter) < > (which may or may not make sense, seems not to). (I used boost::function just to make the example clear). Here is the code to make this work, i.e. use phoenix and units in a expression, (sorry again if I am not supposed to mess with phoenix internals in this way): namespace boost{ namespace phoenix{ #define RESULT_OF_QUANTITY_UNITS_GEN( PhoenixopnamE, UnitsopnamE ) \ template \ struct result_of_##PhoenixopnamE < \ boost::units::quantity &, \ boost::units::unit \

{ \ typedef \ typename boost::units::UnitsopnamE##_typeof_helper< \ boost::units::quantity, boost::units::unit \ >::type type; \ }; RESULT_OF_QUANTITY_UNITS_GEN(multiplies, multiply) RESULT_OF_QUANTITY_UNITS_GEN(divides , divide ) #undef RESULT_OF_QUANTITY_UNITS_GEN

// this refines the operator* so the phoenix:;operator* is used instead of units::operator* #define REFINE_ARITHMETIC_OPERATORS(PhoenixopnamE, CsymboL) \ template< \ class PhoenixExpr, \ class System, \ class Dim \

\ actor< \ composite< \ PhoenixopnamE##_eval, \ boost::fusion::vector< \ PhoenixExpr, \ value< \ boost::units::unit \ > \ > \

...

\ \ operator CsymboL (const actor<PhoenixExpr>& lhs, const unit& rhs){ \ return compose(lhs, rhs); \ } REFINE_ARITHMETIC_OPERATORS(multiplies, *) REFINE_ARITHMETIC_OPERATORS(divides, /) #undef REFINE_ARITHMETIC_OPERATORS }}