standard on defining method to convert class to string

In Java, the standard is to define the method toString() to return a string representation of a class. Other than overloading operator<<, is there any such standard in C++? I know there are the std::to_string() methods to get a string representation of a number. Does the C++ standard speak of defining the method to_string() to serve similar purpose for a class, or is there a common practice followed by C++ programmers?