3 ms·

And what should be defined behavior? There are quite a few choices that depend on particular situations. Feature designers have no knowledge about what would yo

• Ygg2 3y ago
  Return either value or an EMPTY placeholder. Look Java did it. It returns a nullable value or Optional.
  • FpUser 3y ago
    Then I have to check the result anyways. Same thing
    • mughinn 3y ago
      You should always check The argument is that Rust forces you and in C++ you can forget/the compiler can do what it wants
    • Ygg2 3y ago
      No. In Rust check is there by default, with optional unchecked access. In C++ the safety is off by default and you have to remember to check. It's like Yaml parsers, they had "load_yaml" which is unsafe and "safe_load_yaml" which is the secure option. Imagine no surprise when Rubyists went for shorter safe looking method and got their servers pwned.
      • FpUser 3y ago
        I think you are wrong. I looked and in Rust doc it says that: "Removes the last element from a vector and returns it, or None if it is empty". You better be doing check for "None".
        • LegionMammal978 3y ago
          The check is still there, that's not under dispute. GP is saying that it's still not the "same thing" as C++, since Rust will refuse to compile the code unless you either perform the check, or actively opt into unchecked access. In contrast, C++ will happily compile the code if you unintentionally neglect to perform the check.
          • FpUser 3y ago
            Are you saying that Rust will refuse to compile code that does not explicitly check option return result for empty?
            • __jem 3y ago
              Yes, you cannot use the result without matching on the result/option type.
            • Ygg2 3y ago
              >Are you saying that Rust will refuse to compile code that does not explicitly Depends what you mean by explicit. Look at it like this: pub fn main() { let mut vec : Vec<i32> = vec![]; let x = vec.pop(); println!("{:?}",x); // prints: None } In this case you see the value is missing. vec.pop().expect("I want a value") will panic with "I want a value" because value is empty. And most rigorous way to deal with it is: if let Some(x) = vec.pop() { println!("{:?}",x); } else { println!("EMPTY"); // prints: Empty } will either print value or EMPTY depending on what the vector contains. Types like Result will issue warning that you didn't handle the cases.
              • FpUser 3y ago
                for some reason I can not answer your subsequent reply so I do it here: I looked at your example and played a bit with it and yes I agree with you - compiler does help in this case. My old text: So instead of checking if vector is not empty you check that the return result is not empty. I do not see much difference. If Rust compiler would choke when "else" clause in your example is not present I would understand your point about compiler preventing improper access.
    • deleted 3y ago
      [deleted]