[Boost-users] Re: Streaming boost::optional yields inconsistent output in gcc 3.2.3

From: Eelis van der Weegen (boost-users_at_[hidden])
Date: 2004-02-24 09:36:54

Peter Dimov wrote:
> Eelis van der Weegen wrote:
> 
>>Hi,
>>
>>I defined the following operator to stream optional<char>'s:
>>
>>   std::ostream &
>>     operator<< (std::ostream & os, boost::optional<char> const & op)
>>   {
>>     if (op) os << *op; else os << '_';
>>     return os;
>>   }
>>
>>Now, when I use:
>>
>>   boost::optional<char> a ('a');
>>   std::cout << a;
>>
>>'a' is printed like I expected. However, when I use:
>>
>>   std::ostream_iterator<boost::optional<char> > oi (std::cout);
>>   *oi = a;
>>
>>'1' is printed and my operator is apparently ignored (I expected
>>another 'a'). Is this a gcc (3.2.3) issue or a boost issue?
> 
> 
> Neither. Your operator<< definition should be in namespace boost.

Thanks a lot! For some reason I hadn't thought of potential namespace 
lookup issues but of course it makes perfect sense.