Re: [Boost-users] C++ guru required!

Subject: Re: [Boost-users] C++ guru required!
From: Nathan Ridge (zeratul976_at_[hidden])
Date: 2012-02-27 00:26:09

>   > Sorry it took me a bit longer, but here are my ideas.... 
>  > Code from Slide 12 of Andrei's presentation at Going Native 2012: 
>  > 
>  > 
>  > template<class T> 
>  > struct container 
>  > { 
>  >   ... 
>  >   static if(debug_mode<T>::value) 
>  >   { 
>  >     class const_iterator { ... }; 
>  >     static if(std::is_const<T>::value) 
>  >     { 
>  >       typedef const_iterator iterator; 
>  >     } 
>  >     else 
>  >     { 
>  >       class iterator { ... }; 
>  >     } 
>  >   } 
>  >   else 
>  >   { 
>  >     class const_iterator { ... }; 
>  >     clas iterator { ... }; 
>  >   } 
>  > }; 
>  > 
> and my view would be that removing the "static" wouldn't change 
> anything in the program - so why is it necessary. 
>  
>  > template<class PointerWrapper> 
>  > struct grab_pointer_type 
>  > { 
>  >   static if(has_element_type<PointerWrapper>::value) 
>  >   { 
>  >     typedef typename PointerWrapper::element_type pointer_type; 
>  >   } 
>  >   else 
>  >   { 
>  >     typedef typename PointerWrapper::value_type pointer_type; 
>  >   } 
>  > }; 
>  
> also in this example, removing the static wouldn't change the 
> program in any way. 

But the static_if is being used at class scope here - regular
if statements cannot be used at class scope!

Regards,
Nate