Important reminder just in the Preface :-)
Takeaway #1: "C and C++ are different: don’t mix them, and don’t mix them up"
replies(6):
Takeaway #1: "C and C++ are different: don’t mix them, and don’t mix them up"
Where "mixing C/C++" is helpful:
- I "mix C in with my C++" projects because "sqlite3.c" and ffmpeg source code is written C. C++ was designed to interoperate with C code. C++ code can seamlessly add #include "sqlite3.h" unchanged.
- For my own code, I take advantage of "C++ being _mostly_ a superset of C" such as using old-style C printf in C++ instead of newer C++ cout.
Where the "C is a totally different language from C++" perspective is helpful:
- knowing that compilers can compile code in "C" or "C++" mode which has ramifications for name mangling which leads to "LINK unresolved symbol" errors.
- knowing that C99 C23 has many exceptions to "C++ is a superset of C" : https://en.wikipedia.org/wiki/Compatibility_of_C_and_C%2B%2B...
The modern fmt-inspired std::print and std::println etc. are much nicer, preserving all the type checking but losing terrible ideas like stored format state, and localisation by default. The biggest problem is that today C++ doesn't have a way to implement this for your own types easily, Barry illustrates a comfortable way this could work in C++ 26 via reflection which on that issue closes the gap with Rust's #[derive(Debug)].
cin >> a;
Then the program goes berserk as soon as the first non-number is read out of standard input. All the other "cin >> integer" lines are immediately skipped.
Yes, I know about error checking, clearing error condition, discarding characters. But it's a whole lot of stuff you need to do after every single "cin>>" line. It makes the simplicity of cin not worth it.
You check error for the whole batch.
* Performance
* Support for localization (as the format string and positions of values to format differ between languages).
* Code reuse & dogfooding - the data structures used in iostreams are not used elsewhere, and vice-versa
* C and OS interoperability - as you can't wrap a stream around a FILE* / file descritor
* bunch of other stuff...
iostreams work, but are rather crappy.
The less C the merrier.
If you care about correct use of localisation, standard C and C++ libraries aren't really what you're looking for, or even C and C++ to start with.
The only reason why iostreams are slow is because of its incompatible buffering scheme, and the fact that C and C++ need to stay in sync when linked together. And that brand of slow is still faster than other languages, except sometimes those that delegate i/o to pure C implementations.
I agree. It's lunacy. just be explicit and use functions or equivalent like literally every other language.
> If you care about correct use of localisation, standard C and C++ libraries aren't really what you're looking for, or even C and C++ to start with.
fscanf (STDIN, "%d", &a);
in both cases, you need error checking (which you "know about").
I believe Rust has adopted similar idioms. I’ve heard the overall idea referred to as Railway-oriented programming.
In C++ you could implement it with exceptions, though they bring in a bunch of their own baggage that you don’t have to deal with when using monads.