#include <iostream>
#include <type_traits>

template<bool B, class T = void>
struct enable_if_not {};
template<class T>
struct enable_if_not<false, T> { typedef T type; };

class base {};
class child:public base{};
class stream {};

template<class T>
stream& operator << (stream& out, const typename enable_if_not<std::is_base_of<base,T>::value,T>::type& o) {
    std::cout << "some other: " << o << std::endl;
    return out;
}
stream& operator << (stream& out, const base& obj) {
    std::cout << "object was " << std::endl;
    return out;
}

int main() {
    stream out;
    base bo;
    child co;
    out << "hello" << 111ul << bo << std::string("co") << co;
}

stream& operator << (stream& out, const base& obj) {
    std::cout << "object was " << std::endl;
    return out;
}
template<class T>
typename enable_if_not<std::is_base_of<base,T>::value,stream>::type& operator << (stream& out, const T& o) {
    std::cout << "some other: " << o << std::endl;
    return out;
}

some_place << "вот первый виджет: " << some_widget << "&lt; br / &gt;";
for(int i=0;i<wcontainer.size();i++)
     some_place << "вот виджет номер " << i << ": " << wcontainer[i] << "&lt; br / &gt;";