Rust can be difficult to learn and frustrating, but it's also very exciting

Post by bb88 » Wed, Oct 24, 2018, 2:00 AM UTC

Tuna-Fish wrote: post #168

ovao wrote: post #120

Earlier quoted context omitted.

Writing certain data structures in safe Rust can be hard, but not impossible. I’m not aware of any data structures that simply cannot be written in Rust.

Of course, since anything that can be written in C can be written in unsafe Rust. Though, reading the post above yours, I was thinking more about the use of data structures than the implementation of them. In C++, when faced by the need to efficiently iterate through a data structure in different, incompatible orders, the tool of choice is often just to make intrusive linked lists with multiple next pointers per elem…

Post by thethirdone » Wed, Oct 24, 2018, 2:23 AM UTC

igouy wrote: post #244

thethirdone wrote: post #135

Earlier quoted context omitted.

> but it's performance is closer to Java, which is a few orders of magnitude slower than C++ A few order of magnitude is an exaggeration. A more reasonable expectation is a 5x slowdown [1]. Depending on your task, a few orders of magnitude can be correct for JVM based languages; they can have very poor startup times (compared to c++) [2]. However, in startup time, go is not similar to Java. [1]: https://benchmarksgam…

> JVM based languages; they can have very poor startup times (compared to c++) [2] Hello world :-) And is 54.55 ms perceptable? (310.81 ms should be).

Post by otabdeveloper1 » Wed, Oct 24, 2018, 9:51 AM UTC

setr wrote: post #242

otabdeveloper1 wrote: post #201

Earlier quoted context omitted.

State of the art is pthreads and mutexes. The C++ and Rust wrappers for them are roughly equivalent. Rust has some nice features for handling ownership semantics, but they are not significantly better than those in C++. Meanwhile, Rust still lacks a normal exception handling story. Exception handling is absolutely necessary in 2018 for building real software systems. (And even though Rust claims that errors are nicel…

Haven't spent that much time with rust, but so far Result has sufficed for all my exception-needs; it's not clear to me what the practical difference is between exceptions and result , that would be relevant to implementing real software systems? As I understand it, the primary usage of both is to report, and handle, errors. Rust splits it as panic! and Result , where panic! is naturally left for logic errors (ie sta…

Post by qwertycrackers » Wed, Oct 24, 2018, 1:42 PM UTC

otabdeveloper1 wrote: post #255

setr wrote: post #242

Earlier quoted context omitted.

Haven't spent that much time with rust, but so far Result has sufficed for all my exception-needs; it's not clear to me what the practical difference is between exceptions and result , that would be relevant to implementing real software systems? As I understand it, the primary usage of both is to report, and handle, errors. Rust splits it as panic! and Result , where panic! is naturally left for logic errors (ie sta…

> I'm not sure how often you want to recover from such a state though. Pretty much always in real systems software. Imagine a multithreaded server that handles HTTP requests. A catastrophic invariant failure when handling one requests shouldn't bring down the whole server. Or imagine an application that calls into a money transaction routine. (This routine can itself call other routines, and so on for 12 stack frames…

Post by mbrubeck » Wed, Oct 24, 2018, 2:15 PM UTC

MarkovUnchained wrote: post #161

zlynx wrote: post #147

Earlier quoted context omitted.

Actual problems like: - sending dangling references to thread functions. Lambdas with automatic reference capture creating threads from inside functions that exit are terrible here. - returning a pointer or reference to an invalidated iterator - returning a pointer or reference to the contents of a temporary Yes indeed, C++ programmers never actually have these problems, they are purely imaginary. /sarc

Yeah, I don't think there is a professional C++ developer who has any of these problems. It's called static analysis... welcome to a decade ago. Why on earth would an organisation move their codebase to Rust when they can just run Clang? Which they should be doing anyway.....

    #include 
    #include 
    #include 

    int main() {
      std::string s = "Hellooooooooooooooo ";
      std::string_view sv = s + "World\n";
      std::cout