Improve documentation for unreachable #19316
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steveklabnik
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| /// // The above loop always returns, so we must hint to the | ||
| /// // type checker that it isn't possible to get down here | ||
| /// | ||
| /// unreachable!(); |
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I see a few problems with this example:
- The function name is misspelled: it should read
get_at_least_100. - The function should return
u32, not(). sumis never declared (let mut sum = 0;at the start of the function should work).- Perhaps most importantly, the
unreachable!()here is unnecessary (it throws a warning for unreachable code) and can be removed, as the compiler can already verify that the only way theloopcan be exited (besides panicking) is with areturn.
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Whoops! All good points...
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| /// Some(n) if n >= 0 => println!("Some(Non-negative)"), | ||
| /// Some(n) if n < 0 => println!("Some(Negative)"), | ||
| /// Some(_) => unreachable!(), // compile error if commented out | ||
| /// None => println!("None") |
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Fixes #18876