25 lines
647 B
Plaintext
25 lines
647 B
Plaintext
#![feature(conservative_impl_trait)]
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fn main() {
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let cube = |x: f64| x.powi(3);
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let cube_root = |x: f64| x.powf(1.0 / 3.0);
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let flist : [&Fn(f64) -> f64; 3] = [&cube , &f64::sin , &f64::cos ];
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let invlist: [&Fn(f64) -> f64; 3] = [&cube_root, &f64::asin, &f64::acos];
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let result = flist.iter()
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.zip(&invlist)
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.map(|(f,i)| compose(f,i)(0.5))
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.collect::<Vec<_>>();
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println!("{:?}", result);
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}
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fn compose<'a, F, G, T, U, V>(f: F, g: G) -> impl 'a + Fn(T) -> V
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where F: 'a + Fn(T) -> U,
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G: 'a + Fn(U) -> V,
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{
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move |x| g(f(x))
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}
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