Comment by pansa2
19 days ago
Yeah, you could argue that choosing C is just choosing a particular subset of C++.
The main difference from choosing a different subset, e.g. “Google C++” (i.e. writing C++ according to the Google style guide), is that the compiler enforces that you stick to the subset.
C's string handling is so abominably terrible that sometimes all people really need is "C with std::string".
Oh, and smart pointers too.
And hash maps.
Vectors too while we're at it.
I think that's it.
When I developed D, a major priority was string handling. I was inspired by Basic, which had very straightforward, natural strings. The goal was to be as good as Basic strings.
And it wasn't hard to achieve. The idea was to use length delimited strings rather than 0 terminated. This meant that slices of strings being strings is a superpower. No more did one have to constantly allocate memory for a slice, and then keep track of that memory.
Length-delimited also super speeded string manipulation. One no longer had to scan a string to find its length. This is a big deal for memory caching.
Static strings are length delimited too, but also have a 0 at the end, which makes it easy to pass string literals to C functions like printf. And, of course, you can append a 0 to a string anytime.
Just want to off-topic-nerd-out for a second and thank you for Empire.
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I agree on the former two (std::string and smart pointers) because they can't be nicely implemented without some help from the language itself.
The latter two (hash maps and vectors), though, are just compound data types that can be built on top of standard C. All it would need is to agree on a new common library, more modern than the one designed in the 70s.
I think a vec is important for the same reason a string is… because being able to properly get the length, and standardized ways to push/pop from them that don’t require manual bounds checking and calls to realloc.
Hash maps are mostly only important because everyone ought to standardize on a way of hashing keys.
But I suppose they can both be “bring your own”… to me it’s more that these types are so fundamental and so “table stakes” that having one base implementation of them guaranteed by the language’s standard lib is important.
why not std::string?
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The C++ std::string is both very complicated mechanically and underspecified, which is why Raymond Chen's article about std::string has to explain three different types (one for each of the three popular C++ stdlib implementations) and still got some details wrong resulting in a cycle of corrections.
So that wouldn't really fit C very well and I'd suggest that Rust's String, which is essentially just Vec<u8> plus a promise that this is a UTF-8 encoded string, is closer.
https://bkaradzic.github.io/posts/orthodoxc++/
Yeah, WG14 has had enough time to provide safer alternatives for string and arrays in C, but that isn't a priority, apparently.
Add concurrency and you more or less came up with same list C's own creator came up when he started working on a new language.
And constructors and destructors to be able to use those vectors and hash maps properly without worrying about memory leaks.
And const references.
And lambdas.
C is not a subset of C++, there are some subtle things you can do in C that are not valid C++
It is when compared with C89, also the ISO C++ requires inclusion of ISO C standard library.
The differences are the usual that occur with guest languages, in this case the origin being UNIX and C at Bell Labs, eventually each platform goes its own merry way and compatibility slowly falls apart with newer versions.
In regards to C89 the main differences are struct and unions naming rules, () means void instead of anything goes, ?: precedent rules, implicit casts scenarios are reduced like from void pointers.
Some subtle and some not so subtle.
Linters etc... Validates the subset you're choosing to use for your project too.