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https://github.com/ahgamut/rust-ape-example.git
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47 lines
1.2 KiB
Rust
47 lines
1.2 KiB
Rust
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// ./src/std/option.md
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// An integer division that doesn't `panic!`
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fn checked_division(dividend: i32, divisor: i32) -> Option<i32> {
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if divisor == 0 {
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// Failure is represented as the `None` variant
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None
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} else {
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// Result is wrapped in a `Some` variant
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Some(dividend / divisor)
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}
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}
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// This function handles a division that may not succeed
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fn try_division(dividend: i32, divisor: i32) {
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// `Option` values can be pattern matched, just like other enums
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match checked_division(dividend, divisor) {
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None => println!("{} / {} failed!", dividend, divisor),
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Some(quotient) => {
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println!("{} / {} = {}", dividend, divisor, quotient)
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},
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}
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}
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fn part0() {
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try_division(4, 2);
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try_division(1, 0);
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// Binding `None` to a variable needs to be type annotated
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let none: Option<i32> = None;
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let _equivalent_none = None::<i32>;
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let optional_float = Some(0f32);
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// Unwrapping a `Some` variant will extract the value wrapped.
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println!("{:?} unwraps to {:?}", optional_float, optional_float.unwrap());
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// Unwrapping a `None` variant will `panic!`
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println!("{:?} unwraps to {:?}", none, none.unwrap());
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}
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pub fn main() {
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part0();
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}
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