35 lines
1.2 KiB
Rust
35 lines
1.2 KiB
Rust
// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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enum Nil {Nil}
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struct Cons<T> {head:int, tail:T}
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trait Dot {fn dot(&self, other:Self) -> int;}
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impl Dot for Nil {
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fn dot(&self, _:Nil) -> int {0}
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}
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impl<T:Dot> Dot for Cons<T> {
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fn dot(&self, other:Cons<T>) -> int {
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self.head * other.head + self.tail.dot(other.tail)
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}
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}
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fn test<T:Dot> (n:int, i:int, first:T, second:T) ->int {
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//~^ ERROR: reached the recursion limit during monomorphization
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match n {
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0 => {first.dot(second)}
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// Error message should be here. It should be a type error
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// to instantiate `test` at a type other than T. (See #4287)
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_ => {test (n-1, i+1, Cons {head:2*i+1, tail:first}, Cons{head:i*i, tail:second})}
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}
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}
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pub fn main() {
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let n = test(1, 0, Nil, Nil);
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println!("{}", n);
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}
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