• robinm@programming.dev
    link
    fedilink
    arrow-up
    5
    ·
    10 months ago

    That’s a very nicecly written article.

    Just a quick question, isn’t point 8 outdated (misconctption: “Rust borrow checker does adanced liftime analysis”) due to the introduction NLL (no lexical lifetime) in Rust 2018?

    • hairyballs@programming.dev
      link
      fedilink
      arrow-up
      1
      ·
      edit-2
      10 months ago

      There are still obvious things the BC cannot get. For example:

      struct Foo;
      
      impl Foo {
          fn num(&mut self) -> usize { 0 }
          fn index(&mut self, _i: usize) { }
      }
      
      let foo = Foo;
      foo.index(foo.num()); //error
      
      • sirdorius@programming.dev
        cake
        link
        fedilink
        arrow-up
        2
        ·
        edit-2
        10 months ago

        This looks like a pretty easy fix that the compiler could do by extracting the argument to a temp variable to improve the syntax of the language.

      • KillTheMule@programming.dev
        link
        fedilink
        arrow-up
        1
        ·
        edit-2
        10 months ago

        Note that when you change num to take &self instead, this works out (you also need to mark foo as mutable, of course).

        • hairyballs@programming.dev
          link
          fedilink
          arrow-up
          1
          ·
          10 months ago

          It’s a toy example. In that case, the solution is to assign the expression to a variable to compute its result upfront.