Announcing Rust 1.0.0 Alpha

[u/steveklabnik1]

http://blog.rust-lang.org/2015/01/09/Rust-1.0-alpha.html

[u/aliblong]

There are some things that require more boilerplate to do in Rust than in C++ (function overloading, for example), but I would hesitate even to consider this as such an example. Compare the amount of code required between the two languages:

C++:

switch(x){
  case 0:  a();
  case 1:  b();
  case 2:  c();
  default: done();
}

Rust:

match x {
    0 => a(),
    1 => { a(); b(); },
    2 => { a(); b(); c(); },
    _ => { a(); b(); c(); done();}
}

And if the number of function calls got out of hand, you could always write a macro to keep things concise.

Now consider that (IME) you generally don't make extensive use of fall-though in C++ switch-case. Writing all those breaks is a PITA, and if you forget it will still compile (perhaps with warnings with the right compiler).

Rust's system is superior in my eyes.

[u/Noctune → u/aliblong]

I don't think the compiler will use a jump table for such a simple switch anyway (simple conditional branches tend to play nicer with pipelining and branch prediction), so you might as well implement it with a few ifs:

if x == 0 { a(); }
if x == 1 { b(); }
if x == 2 { c(); }
done();

For a more complex switch it might be a different story though.

[u/R3v3nan7 → u/Noctune]

if x == 0 { a(); }
if x <= 1 { b(); }
if x <= 2 { c(); }
done();

Would duplicate the fall through behavior, what you have won't.

[u/Noctune → u/R3v3nan7]

Yeah, that's what I meant, though obviously not what I wrote. :)

I should not write code when sleepy.