None. Just use a simple function call like almost every other language. Why is

    std::cout::write(myInt)

such a hard thing to write that we decided

    std::cout << myInt

was a better idea?

Disclaimer: I dislike iostreams and in our environment <iostream> is completely banned.

However, in C++98, how else would you handle when you have an arbitrary number of things to print in a type-safe way? e.g.

    cout << myInt << ": " << something << " - " << otherthing << " - " << etc << '\n';

printf is not type-safe, nor supports user defined types. I'd rather not write 8 lines of functions calls for the same thing either.

I think it made some sense C++98, though it is an awful API in 2021.

std::cout::write(myInt,": ",something," - ",otherthing," - ",etc,'\n');

Possible with preprocessor.

I'm not sure how that could be done before variadic templates were introduced in C++11.

I doubt that's possible with the C++98 preprocessor.

> However, in C++98, how else would you handle when you have an arbitrary number of things to print in a type-safe way? e.g.

If I were the one designing the language, I'd have simply fixed printf to be type-safe. (e.g. via adding macro support a la Lisp)

If I have to guess, it's probably to support operator overloading (printing custom data type) without requiring OOP e.g. must be a class that implements Writable

> What operator would you have used?

Qt does it right: fluent-style interface which does string interpolation.

Is that localizable, or does it compile the interpolated string into code so it can't be replaced?

Qt has a pretty extensive localization framework. You would probably want to wrap both strings in tr(). https://doc.qt.io/qt-5/i18n-source-translation.html