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

From: John C. Femiani (john.femiani_at_[hidden])
Date: 2008-07-17 17:51:47

Michiel Helvensteijn wrote:
> John C. Femiani wrote:
>
>   
>>>> or to specialize boost::test_tools::tt_detail::print_log_value.
>>>>     
>>>>         
>>> This I didn't try. It seemed a bit more hack-ish and a bit more work.
>>>       
>> Well both legal solutions involve using something from a 'detail'
>> namespace, which scares me.
>>     
>
> 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?
>
>   
Perhaps an overloadable ::boost::repr(T) function that translates T into 
a proxy type that can have operator<< overloaded properly.

e.g. (untested)

namespace boost{
    template<class T> T const & repr(T const & arg) {
        return arg;
    }
}

namespace boost{
     template<class T>
     std::string repr(std::vector<T> const& arg) {
          std::ostringstream dst;
          typename std::vector<T>::iterator i = arg.begin()
          dst << '{' << repr(*i++);
          while(i != arg.end())
              dst << ',' << repr(*i++);
          dst << '}';
          return dst.str();
     }
}

BTW: I think you can write a ::boost::iterator_range to a stream. 
(haven't tried from a test macro though).

I bet that would be useful for test, program_options, lexical_cast, etc. 
(If something similar does not already exist).

--John