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> Maybe fmt fixes these problems, I don't know. Yeah, it looks like you did a lot of guesswork in that comment, and a lot of those guesses were inaccurate. Not really trying to be hostile here, but you did acknowledge that you were unfamiliar with std::format. The part that fmtlib / std::format has, which is printf-like, is the idea of having a format string and arguments, rather than having a bunch of separate, piecemeal strings. // Old printf code, works ok for most people
std::printf("failed to clone %s from %s", target, src);
// <iostream>
std::cout << "failed to clone " << target << " from " << src;
// New std::format / fmtlib
std::print("failed to clone {} from {}", target, src);
You can see that you don't need to remember what kind of format specifier you need. This is C++, and that kind of problem is solved with overloading.The std::print interface can work equally well with FILE or std::ofstream, or whatever you want. This is C++, and so you can just use a templated output iterator—or one of the overloads that creates one automatically. There are a lot of problems with <iostream>. I think it’s telling that lots of languages have copied printf, but nobody (or almost nobody) thought <iostream> was good enough to copy. There are just too many serious design flaws with <iostream>. It would be one thing if <iostream> were just annoying to use, but it poses problems for localization, thread-safety, accidental misuse through its statefulness, and its operator overloading syntax is bad. |
It's Bjarne (Stroustrup)'s pet feature. You'll notice that many expert practitioners of C++ write std::println("Hello, world"); or similar for a canonical C++ 23 Hello World, but Bjarne pointedly still writes it with std::cout and the iostream operator overloads.
Now that Bjarne is back at Columbia teaching, there's a risk he'll infect impressionable young people with this nonsense, COMSW4995 was not an intro class and I suspect Bjarne's jetsetting makes it impractical to teach such a class, so this risk is small but not zero.