Re: [Boost-users] [test] BOOST_CHECK_EQUAL type to stream

From: John C. Femiani (john.femiani_at_[hidden])
Date: 2008-07-23 16:15:46

Gennadiy Rozental wrote:
> Michiel Helvensteijn <m.helvensteijn <at> gmail.com> writes:
>   
>> Hm, yes. You're afraid they will change the structure of that namespace from
>> under our feet without even putting it in a changelog.
>>
>> Given that possibility, might it not be better to put it in namespace std
>> anyway...
>>
>> Perhaps they should offer us a real solution in the next version?
>>     
>
> 'They' are open to any suggestions ;)
>
> Gennadiy
>
>   
I suggested that boost should actually only print adapters to the 
stream. The default behavior would be to

    template<class T>
    struct repr_type{
            typedef T type;
            T make(T value) {return value;}
    };

    template<class T>
    typename repr_type<T>::type repr(T& value) {
           return repr_type<T>::make(value);
    }

Then to print log messages:

    stream <<  repr<>(obj1) <<  repr<>(obj2);

and to customize output when overloading operator << is not possible, 
you can use template specialization.

    template<class T> struct repr_type<std::vector<T> > {...}

--John