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I've tried to learn Rust twice because i think it's great idea (memory safety with C++ performance) BUT... Rust seems even more complicated than C++ for me, rea

by lossolo 10y ago

I've tried to learn Rust twice because i think it's great idea (memory safety with C++ performance) BUT... Rust seems even more complicated than C++ for me, really i find C++11/14 a lot easier to reason about than Rust. I am not sold on functional programming also. Dangling pointers/memory leaks are problems of C and old C++ but not modern C++. I don't remember when i last seen any memory problems in modern c++ code base where ownership is encapsulated inside smart pointers. I think Rust is great and would have a lot more attention and adoption if version 1.0 would ship in 2009. I think Rust is too late into the game. That's why probably only mozilla is really using it and dropbox for really small part of their infrastructure from known players. From what i researched big part of "friends" that use Rust in production are using it because of hype? I am not sure exactly why but some of their use cases for sure not need systems programming language. Maybe it will not end up like D which tried to solve similar problem. EDIT: It's funny how people down vote my personal feelings about the language without any anti-argument or comment. It seems having other opinion than "Rust is GREAT" is not desirable here.

Rusky 10y ago
Probably getting downvoted because the assertion that modern C++ solves memory leaks is getting kind of tired as far as Rust discussions go, and is also missing the point. Rust doesn't solve memory leaks, it solves memory unsafety- things like use-after-free and iterator invalidation that modern C++ does virtually nothing to help with, and that vulnerability statistics show are still huge problems with programs written in C++.
- dbaupp 10y ago
  I wrote something on the memory leak vs. memory unsafety confusion a while ago, for those interested in exploring it more: http://huonw.github.io/blog/2016/04/memory-leaks-are-memory-safe/ http://huonw.github.io/blog/2016/04/memory-leaks-are-memory-...
- lossolo 10y ago
  I don't see usage of new/free without encapsulation, this is not modern c++ which invalidates your point. Using naked new/free is depreciated in modern c++ and is problem of C not modern C++. What kind of statistics? Can you give any links that support what you wrote? All memory leaks/buffer overflows that i saw lately are associated with C (openssl, libc etc) not with C++. For iterator invalidation there are couple of simple rules to remember or for example you can use std::insert_iterator that will not be invalidated even if relocation occurs. You could use static analyzer and would avoid most of the problems. EDIT: My point is that i have nothing to gain from rust when knowing c++ and memory management rules + i got good static analyzer. But probably for someone that do not know C++ at all Rust could be a better choice.
  - Rusky 10y ago
    Sticking the free in a destructor doesn't help you at all with memory safety, it just makes it easier to avoid leaks. Simple rules are, again according to the evidence, not good enough. There are simple rules you can follow in C as well. The benefit of Rust (as far as memory safety goes) is that the compiler enforces those rules. In fact, the mechanism by which it does this (lifetimes) is typically what makes Rust seem more complicated to beginners. But the fact is, that complication is still there in C and C++, the compiler just lets you deal with it all on your own.
    - lossolo 10y ago
      Yes i understand what your point is. I do not need to know/remember certain rules because compiler is doing this for me in Rust, my point is that if someone knows those rules in C++ and have good static analyzer he can get similar safety. I will try third time with Rust, i just feel sometimes like in shackles in Rust, i would like to say to compiler hey i know what i am doing, like i can do in C++.
      - pcwalton 10y ago
        > my point is that if someone knows those rules in C++ and have good static analyzer he can get similar safety. No. The entire history of large-scale security-critical applications in C++ disagrees with you. > I will try third time with Rust, i just feel sometimes like in shackles in Rust, i would like to say to compiler hey i know what i am doing, like i can do in C++. That's precisely what unsafe is for.

by lossolo 10y ago

Rusky 10y ago

Probably getting downvoted because the assertion that modern C++ solves memory leaks is getting kind of tired as far as Rust discussions go, and is also missing the point. Rust doesn't solve memory leaks, it solves memory unsafety- things like use-after-free and iterator invalidation that modern C++ does virtually nothing to help with, and that vulnerability statistics show are still huge problems with programs written in C++.

dbaupp 10y ago
I wrote something on the memory leak vs. memory unsafety confusion a while ago, for those interested in exploring it more: http://huonw.github.io/blog/2016/04/memory-leaks-are-memory-safe/ http://huonw.github.io/blog/2016/04/memory-leaks-are-memory-...
lossolo 10y ago
I don't see usage of new/free without encapsulation, this is not modern c++ which invalidates your point. Using naked new/free is depreciated in modern c++ and is problem of C not modern C++. What kind of statistics? Can you give any links that support what you wrote? All memory leaks/buffer overflows that i saw lately are associated with C (openssl, libc etc) not with C++. For iterator invalidation there are couple of simple rules to remember or for example you can use std::insert_iterator that will not be invalidated even if relocation occurs. You could use static analyzer and would avoid most of the problems. EDIT: My point is that i have nothing to gain from rust when knowing c++ and memory management rules + i got good static analyzer. But probably for someone that do not know C++ at all Rust could be a better choice.
- Rusky 10y ago
  Sticking the free in a destructor doesn't help you at all with memory safety, it just makes it easier to avoid leaks. Simple rules are, again according to the evidence, not good enough. There are simple rules you can follow in C as well. The benefit of Rust (as far as memory safety goes) is that the compiler enforces those rules. In fact, the mechanism by which it does this (lifetimes) is typically what makes Rust seem more complicated to beginners. But the fact is, that complication is still there in C and C++, the compiler just lets you deal with it all on your own.
  - lossolo 10y ago
    Yes i understand what your point is. I do not need to know/remember certain rules because compiler is doing this for me in Rust, my point is that if someone knows those rules in C++ and have good static analyzer he can get similar safety. I will try third time with Rust, i just feel sometimes like in shackles in Rust, i would like to say to compiler hey i know what i am doing, like i can do in C++.
    - pcwalton 10y ago
      > my point is that if someone knows those rules in C++ and have good static analyzer he can get similar safety. No. The entire history of large-scale security-critical applications in C++ disagrees with you. > I will try third time with Rust, i just feel sometimes like in shackles in Rust, i would like to say to compiler hey i know what i am doing, like i can do in C++. That's precisely what unsafe is for.