[Boost-users] Re: boost::variant output a vector?

From: Frank Birbacher (bloodymir.crap_at_[hidden])
Date: 2004-11-21 13:15:01

Hi!

Bo Peng wrote:
> However, I can not output a variant vector work by defining ostream&
> operator<< vector<double> . Attached is a test case. Note that variant
> int, string can be outputed, but not the vector. Yet, cout <<
> vector<double> is working.

The problem is not in the variant itself, but it the function 
lookup of C++: Your operator << is neither defined in the 
namespace of the ostream (which is std::) nor defined in the 
namespace from where it is called (which is boost::). That's why 
the compiler does not find your function when using the variant.
   You must not put anything into the std namespace but function 
overloads AFAIK. So try to put your operator << into the 
namespace std. You can search throu the newsgroup 
comp.lang.cpp.moderated for further information.

Frank