I care about performance, when it actually matters to acceptance testing.
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.
> 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.
_("some text") ... aka gettext and friends.
C and C++ are the bedrock of operating systems with the best performance and extensive support for all languages.
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.
Historical baggage, they weren't the first system programming languages, got lucky with UNIX's license allowing for widespread adoption, and won't be the last one standing either.