Hi! I came up with a I/O weird behaviour with boost::tuple. In the following example program: #include #include #include <iostream> #include <sstream> int main() { using namespace std ; using namespace boost ; typedef ::boost::tuple< float > tuple_type ; float v ; tuple_type t ; string str = "0.1" ; istringstream str_in( str ) ; str_in >> v ; if ( str_in >> t ) { cout << "yes " ; } else { cout << "no " ; } cout << t << endl ; return 0 ; } I expect the output to be "no (0)", but I get "yes (0)". Usually, I expect operator>> with streams to change the state of the stream to some kind of failure state if it could not read the requested type. For example if I replace the 'if' with the following: if ( str_in >> t.get< 0 >() ) then I get "no (0)". Although I know it is not the equivalent to reading the tuple t directly (no open/close character), at least I get the error set I as expected. If the end of input (eof) as been read before reading the tuple, then the condition will be false. So, I am wrong to expect such a behavior? Or is there a bug here (either in the way I use it or in the tuple's input operator)? If it matters, the compiler used is g++ 4.0. Thanks, -- François Duranleau LIGUM, Université de Montréal "Do you want to use a machine, or do you want the machine to use you?" - Doohan, in _Cowboy Bebop_