How can I check if a class has operator<< defined for it?

Question

How can I check if std::cout << myClass; is valid? I'd like to do something like:

class Logger {
 public:
  // Some kind of enable_if(operator<< doesn't exist)
  void printMyClass(MyClass& my_class) {
    std::cout << "Got a myclass" << std::endl;
  }   

  // Some kind of enable_if(operator<< exists)
  void printMyClass(MyClass& my_class) {
    std::cout << "Got a myclass: " << my_class << std::endl;
  }   

};