There's the lazy solution:
std::vector<int> v; std::copy(v.begin(), v.end(), std::ostream_iterator<int>(cout, ", "));
But that has the problem of printing an extra comma at the end.
More generically, you can do:
template<typename T>
ostream& write_container(ostream &s, const T &container)
{
bool first = true;
cout << "{ ";
for( typename T::const_iterator it = container.begin(); it != container.end(); ++it )
{
if( first )
first = false;
else
cout << ", ";
cout << *it;
}
cout << " }";
return s;
}However, you cannot overload operator<< to do this. Since containers have no common base class, the only way to do this is using templates, and the above template declaration matches basically any type. Doing the above with operator<< would make operator<< ambiguous for any type with its own operator<<, and produce some seriously weird errors.
If you insist on overloading operator<<, I think the solution using boost::enable_if giving on SO is just about the best you can do.
