Rant disclaimer. Proceed at your own risk.
I want to like Rust, if only because anything has to be better than C++. C++ is godawful and it sucks that all these decades later it’s what serious big software is written in.
But I haven’t found the explanation of Rust and it’s trade offs and philosophy written by someone who can write serious Haskell and Lisp and C++ and is like “Rust. This is the way. Here’s how and why.”
I’m sure there are much better blog posts than this one that shed light on how parametric as opposed to ad-hoc polymorphism is natural in Rust with no runtime cost. Or how Rust’s nested angle-bracket hell to get a pointer to a piece of memory is actually a deep and profound algebra that exposes std::move for the fraud it actually is or whatever.
Where do I find the explanation of why Rust is less awful than C++ written by someone who has written a lot of C++ out of necessity, doesn’t take non-browser JS seriously, doesn’t think 8 boxes need kube, doesn’t stand to make consulting revenue off having been involved in Cargo, and generally uses C++/Python because they’ve got work to do?
Where do I go to see the light as someone who has some idea how brilliant Eich is and also knows how ridiculous it is to use JavaScript when you’ve got an alternative better than Lua? (I’ve written a JavaScript compiler, I know how unfortunate node.js and Electron are).
I want to be sold! Sell me!
It's the only language existing that is memory safe and provides zero cost abstraction to the CPU capabilities (i.e. no mandatory GC, values don't need to be boxed, ability to mutate memory).
The only limitation that may not eventually be removed is the lack of dependent types (although you can kind of emulate them by lifting terms to the type level and using lifetimes to represent variables).
C++ is not memory safe, Lisp has no type system and Haskell has GC, all values are boxed in a closure and it cannot mutate memory safely, so none of these languages are even in contention.
C++ compiled by clang-12, with clang-tidy and cppcheck turned all the way up, with everything owned by a std::unique_ptr, run through ASAN, UBSAN, TSAN etc (which seems to build about as fast as Rust) lets what by that Rust catches?
I’m not being sarcastic, in all earnestness educate me!
Cool that you use all those tools. Wouldn't it be cool to be able to depend on libraries knowing they all use those settings? And you can depend on libraries by putting a single line in a toml file.
I mean C++ dependency management is so bad there is a concept of a header only library so you just have to copy the file into your project with no support for managing versions.
C++ dependency management is so bad people use the OS installed dependcies because they struggle to set up a build environment otherwise.
What I'm saying is that C++ is pretty good and toe to toe C++ with all the tools you describe and Rust are fairly comparable. But with Rust the whole ecosystem uses it so the network effects make things much better. And it's snowballing.
You make a really good point about C++ headers. Textual inclusion of globs of bytes into translation units is 1970s legacy stuff that totally fucks up reasonable build times, and for all the talk about C++20 modules they haven't delivered yet.
I actually think this is one of the things that Rust could crush C++ on, because build times are becoming the whole show on big C++ projects.
It's super weird to me that C++, with this whacky 1970s constraint that totally fucks up modularity, still builds neck-and-neck or better with Rust.
In principle Rust could do *way* better on this, and that is a feature that might get me to consider Rust seriously, no matter how stupid I think the borrow checker is. But Rust still compiles dog slow...