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https://github.com/rust-lang/rust
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36 lines
844 B
Rust
36 lines
844 B
Rust
// Test that closures and coroutines are "must use" types.
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//@ edition:2018
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#![feature(async_closure)]
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#![feature(coroutines)]
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#![deny(unused_must_use)]
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fn unused() {
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|| { //~ ERROR unused closure that must be used
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println!("Hello!");
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};
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async {}; //~ ERROR unused implementer of `Future` that must be used
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|| async {}; //~ ERROR unused closure that must be used
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async || {}; //~ ERROR unused closure that must be used
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[Box::new([|| {}; 10]); 1]; //~ ERROR unused array of boxed arrays of closures that must be used
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vec![|| "a"].pop().unwrap(); //~ ERROR unused closure that must be used
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let b = false;
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|| true; //~ ERROR unused closure that must be used
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println!("{}", b);
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}
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fn ignored() {
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let _ = || {};
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let _ = || yield 42;
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}
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fn main() {
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unused();
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ignored();
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}
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