In some cases unwrap could be useful if you don’t care about a panic or if you know the value can’t be None. Sometimes it’s just used as a shortcut. You can likewise do this in C#:
A panic isn’t the same as an exception though, you can’t ‘catch’ a panic, it’s unrecoverable and the program will terminate more-or-less immediately.
Rust provides a generic type Result<T, E>, T being a successful result and E being some error type, which you are encouraged to use along with pattern matching to make sure all cases are handled.
Not really, because rust doesn’t have exceptions. Instead you are encouraged to handle every possible case with pattern matching. For example:
fn maybe_add_one(number: Option<u8>) -> u8 { match number { None => 0, Some(i) => i + 1, } }Option<u8> is a type which can either be some 8bit unsigned integer, or none. It’s conceptually similar to a
Nullable<int>in C#.In C# you could correctly implement this like:
public int MaybeAddOne(int? number) { if (number.HasValue) { return number.Value + 1; } return 0; }In rust, you can call Unwrap on an option to get the underlying value, but it will panic if the value is None (because None isn’t a u8):
fn maybe_add_one(number: Option<u8>) -> u8 { number.unwrap() + 1 }In some cases unwrap could be useful if you don’t care about a panic or if you know the value can’t be
None. Sometimes it’s just used as a shortcut. You can likewise do this in C#:public int MaybeAddOne(int? number) { return number.Value + 1; }But this throws an exception if number is null.
A panic isn’t the same as an exception though, you can’t ‘catch’ a panic, it’s unrecoverable and the program will terminate more-or-less immediately.
Rust provides a generic type
Result<T, E>, T being a successful result and E being some error type, which you are encouraged to use along with pattern matching to make sure all cases are handled.