3 ms·

Joke's on you: it took me a month of asking around why my program won't compile to figure out I really CAN'T do it without dereferencing inside the function. Th

• CalChris 10y ago
  You probably have a simpler, clearer way of solving that problem than by torturing the language.
  • iopq 10y ago
    I do, but the problem is FizzBuzz. What's the point of solving FizzBuzz in a SIMPLE way? The whole point of FizzBuzz is to torture the language.
    • lisivka 10y ago
      fn main() { for i in 1..101 { if i % 15 == 0 { println!("FizzBuzz"); } else if i % 3 == 0 { println!("Fizz"); } else if i % 5 == 0 { println!("Buzz"); } else { println!("{}", i); } } }
      • flukus 10y ago
        I don't know why people over complicate things. I was searching for other solutions and found this abomination: https://bitbucket.org/iopq/fizzbuzz-in-rust/src/bf4968973d73137f0dfd07205d599bed30a788fa/src/lib.rs?at=master&fileviewer=file-view-default https://bitbucket.org/iopq/fizzbuzz-in-rust/src/bf4968973d73... I hope their production code isn't like this.
        • iopq 10y ago
          I wrote this as an exercise. This is specifically written to be point-free code without any if or match expressions. .unwrap_or_else(|| i.to_string().into()) this is the only one that was too ugly to make point-free
        • Ygg2 10y ago
          Wut? It's about as representative of Rust as writing FizzBuzz using Monads. In Java. If you want production code look at Rust and Servo.
    • flukus 10y ago
      If the problem is FizzBuzz then it's you that's made it too complicated. Here is a simple version: https://github.com/the-guitarman/rust_fizzbuzz/blob/master/src/main.rs https://github.com/the-guitarman/rust_fizzbuzz/blob/master/s...
      • iopq 10y ago
        It doesn't do the same exact thing as mine does. For one thing, mine does FizzBuzzBazz (factors of 3, 5, 7) or even FizzBuzzBazzQuux if you want (actually arbitrary strings and arbitrary conditions)
• openasocket 10y ago
  > This is because of higher ranked lifetime bounds... No, it's because the function you're returning is of type FnMut(&B) -> C, but your F function is of type FnMut(B) -> G. It expects an owned value of B, but you only have a borrowed reference to a B. Just make F of type FnMut(&B) -> G and you no longer have to dereference and no longer need the restriction that B: Copy. Higher-ranked lifetime values don't have anything to do with it. Here's the new version: fn apply<A, B, C, F, G>(mut f: F, a: A) -> impl FnMut(&B) -> C where F: FnMut(&B) -> G, G: FnMut(A) -> C, A: Clone { move |b| f(b)(a.clone()) }
  • iopq 10y ago
    You think I didn't try that one before? It doesn't work in MY case: error[E0281]: type mismatch: the type `fn(_) -> _ {tool::second::<_>}` implements the trait `std::ops::FnMut<(_,)>`, but the trait `for<'r> std::ops::FnMut<(&'r _,)>` is required (expected concrete lifetime, found bound lifetime parameter --> src\lib.rs:50:17 | 50 | .filter(apply(second, i)) | ^^^^^ | = note: required by `apply` error[E0271]: type mismatch resolving `for<'r> <fn(_) -> _ {tool::second::<_>} as std::ops::FnOnce<(&'r _,)>>::Output == _` --> src\lib.rs:50:17 | 50 | .filter(apply(second, i)) | ^^^^^ expected bound lifetime parameter , found concrete lifetime | = note: concrete lifetime that was found is lifetime '_#11r = note: required by `apply` error: aborting due to 2 previous errors error: Could not compile `fizzbuzz`.