69 lines
1.8 KiB
Rust
69 lines
1.8 KiB
Rust
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// Copyright 2018 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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// This test illustrates that under NLL, we can remove our overly
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// conservative approach for disallowing mutations of match inputs.
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// See further discussion on rust-lang/rust#24535 and
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// rust-lang/rfcs#1006.
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// compile-flags: -Z disable-ast-check-for-mutation-in-guard
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#![feature(nll)]
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fn main() {
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rust_issue_24535();
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rfcs_issue_1006_1();
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rfcs_issue_1006_2();
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}
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fn rust_issue_24535() {
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fn compare(a: &u8, b: &mut u8) -> bool {
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a == b
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}
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let a = 3u8;
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match a {
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0 => panic!("nope"),
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3 if compare(&a, &mut 3) => (),
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_ => panic!("nope"),
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}
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}
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fn rfcs_issue_1006_1() {
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let v = vec!["1".to_string(), "2".to_string(), "3".to_string()];
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match Some(&v) {
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Some(iv) if iv.iter().any(|x| &x[..]=="2") => true,
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_ => panic!("nope"),
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};
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}
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fn rfcs_issue_1006_2() {
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#[inline(always)]
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fn check<'a, I: Iterator<Item=&'a i32>>(mut i: I) -> bool {
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i.any(|&x| x == 2)
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}
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let slice = [1, 2, 3];
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match 42 {
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_ if slice.iter().any(|&x| x == 2) => { true },
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_ => { panic!("nope"); }
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};
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// (This match is just illustrating how easy it was to circumvent
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// the checking performed for the previous `match`.)
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match 42 {
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_ if check(slice.iter()) => { true },
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_ => { panic!("nope"); }
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};
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}
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