37 lines
565 B
Rust
37 lines
565 B
Rust
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fn apply<F>(f: F)
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where
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F: FnOnce(),
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{
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f();
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}
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fn apply_to_3<F>(f: F) -> i32
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where
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F: Fn(i32) -> i32,
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{
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f(3)
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}
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fn main() {
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use std::mem;
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let greeting = "hello";
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let mut farewell = "goodbye".to_owned();
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let diary = || {
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println!("I said {}.", greeting);
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farewell.push_str("!!!");
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println!("Then I screamed {}.", farewell);
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println!("Now I can sleep. zzzzz");
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mem::drop(farewell);
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};
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apply(diary);
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let double = |x| 2 * x;
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println!("3 doubled: {}", apply_to_3(double));
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}
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