c++ - Cythonic way to wrap boost::geometry::Point accessors -

what correct cythonic way wrap following member functions of boost::geometry::point? code snippet comes here.

    /// @brief coordinate     /// @tparam k coordinate     /// @return coordinate     template <std::size_t k>     inline coordinatetype const& get() const     { #if defined(boost_geometry_enable_access_debugging)         boost_geometry_assert(m_created == 1);         boost_geometry_assert(m_values_initialized[k] == 1); #endif         boost_static_assert(k < dimensioncount);         return m_values[k];     }      /// @brief set coordinate     /// @tparam k coordinate set     /// @param value value set     template <std::size_t k>     inline void set(coordinatetype const& value)     { #if defined(boost_geometry_enable_access_debugging)         boost_geometry_assert(m_created == 1);         m_values_initialized[k] = 1; #endif         boost_static_assert(k < dimensioncount);         m_values[k] = value;     } 

i first attempted using:

cdef extern "s57/data/geometries.h" namespace "bg::model":     cdef cppclass _geo2 "bg::model::point<double, 2, bg::cs::spherical_equatorial<bg::degree>>":         _geo2()         _geo2( const _geo2& other )         const double get[size_t]() except +         void set[size_t](double) except + 

but don't know go since this:

property x:     def __set__(self, double value):         deref(self._p).set[0](value) 

gives me failure:

error compiling cython file: ------------------------------------------------------------ ...     property x:         def __set__(self, double value):             deref(self._p).set[0](value)                               ^ ------------------------------------------------------------  c:\xxxx\x.pyx:24:31: not parsable type 

my current working solution has been create helper functions like:

double get_geo2_x( geo2& pnt ); double get_geo2_y( geo2& pnt ); void set_geo2_x( geo2& pnt, double value ); void set_geo2_y( geo2& pnt, double value ); 

does have in mind more elegant solution?

you're running problems cython's handling of non-type template parameters. can manually specify function names using strings, inserted directly generated c code (see http://docs.cython.org/src/userguide/external_c_code.html#resolving-naming-conflicts-c-name-specifications)

as simple example

// example.hpp #include <iostream>   class c {   template <int k>   void set(double value) {       std::cout << k << ": " << value << std::endl;   } 

and cython code

cdef extern "example.hpp":     cdef cppclass c:         void set0 "set<0>"(double) except +         void set1 "set<1>"(double) except +    def do_set():     # simple illustrative example     cdef c c     c.set0(1.0)     c.set1(1.5) } 

whenever cython sees set0 called on c substitutes set<0>, calling template function directly. can use properties, trying do.

this isn't better creating helper functions, might little easier.