31 lines
442 B
Rust
31 lines
442 B
Rust
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// run-pass
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#![feature(const_trait_impl)]
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const fn answer_p1<F>(f: &F) -> u8
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where
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F: ~const FnOnce() -> u8,
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F: ~const FnMut() -> u8,
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F: ~const Fn() -> u8,
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{
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f() * 7
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}
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const fn three() -> u8 {
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3
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}
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const fn answer_p2() -> u8 {
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answer_p1(&three)
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}
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const fn answer<F: ~const Fn() -> u8>(f: &F) -> u8 {
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f() + f()
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}
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const ANSWER: u8 = answer(&answer_p2);
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fn main() {
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assert_eq!(ANSWER, 42)
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}
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