Re: [Boost-users] default argument and call trait const_reference

Subject: Re: [Boost-users] default argument and call trait const_reference
From: Hicham Mouline (hicham_at_[hidden])
Date: 2009-04-09 10:11:13

>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,

I've just corrected call_traits<>::const_reference  to
const_reference<>::param_type
because I am dealing with function parameters here, and I still have the
same problem.

Rds,