[Boost-users] default argument and call trait const_reference

Subject: [Boost-users] default argument and call trait const_reference
From: Hicham Mouline (hicham_at_[hidden])
Date: 2009-04-09 09:52:39

Hello,

I have the following template

template<typename C>
class X
{
public:

  template<typename Interp, typename Extrap>
  void Get (int, 
                typename boost::call_traits<Interp>::const_reference=
Interp(),
                typename boost::call_traits<Extrap>::const_reference=
Extrap() ) const;
};

template<typename C>
template<typename Interp, typename Extrap>
inline void X<C>::Get(int, typename
boost::call_traits<Interp>::const_reference i,
                typename boost::call_traits<Extrap>::const_reference e )  {
    // when I get here, 
    i.mOrder is not 2 (0)
    e.mOrder is not 2 (23142343)
}

class P {
public:
  static const size_t defaultInterpolationOrder = 2;  // quadratic
polynomial
  
  Polynomial1D(size_t order =defaultInterpolationOrder)
  : mOrder(order)
  {}
Private: 
  size_t mOrder;
};

1 example of call is 

 x.template GetSpot<P,P>( 5 );

when I debug this P's ctor is never called and mOrder is never 2

Is my GetSpot method valid, the construction of the temporary should be
bound to the const ref
   const P&
and the temporary should have finished being constructed before we go inside
the Get() method.

Is there an issue with the definition of Get being out of classe?

Am I calling call_traits<P>::const_reference in a wrong way?

VS2005SP1

Regards,