dbf994bbaf
associated machinery. Future such attempts should go through lints anyhow. There is a fair amount of fallout in the compile-fail tests, as WF checking now occurs earlier in the process.
29 lines
879 B
Rust
29 lines
879 B
Rust
// Copyright 2012 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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pub trait NumCast: Sized {
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fn from(i: i32) -> Option<Self>;
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}
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pub trait NumExt: PartialEq + PartialOrd + NumCast {}
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impl NumExt for f32 {}
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impl NumCast for f32 {
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fn from(i: i32) -> Option<f32> { Some(i as f32) }
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}
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fn num_eq_one<T: NumExt>(n: T) {
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println!("{}", n == NumCast::from(1).unwrap())
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}
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pub fn main() {
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num_eq_one(1f32); // you need to actually use the function to trigger the ICE
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}
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