diff options
Diffstat (limited to 'src/test/ui/lint/unused/unused-closure.rs')
-rw-r--r-- | src/test/ui/lint/unused/unused-closure.rs | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/src/test/ui/lint/unused/unused-closure.rs b/src/test/ui/lint/unused/unused-closure.rs new file mode 100644 index 000000000..c96c90731 --- /dev/null +++ b/src/test/ui/lint/unused/unused-closure.rs @@ -0,0 +1,35 @@ +// Test that closures and generators are "must use" types. +// edition:2018 + +#![feature(async_closure)] +#![feature(generators)] +#![deny(unused_must_use)] + +fn unused() { + || { //~ ERROR unused closure that must be used + println!("Hello!"); + }; + + async {}; //~ ERROR unused implementer of `Future` that must be used + || async {}; //~ ERROR unused closure that must be used + async || {}; //~ ERROR unused closure that must be used + + + [Box::new([|| {}; 10]); 1]; //~ ERROR unused array of boxed arrays of closures that must be used + + vec![|| "a"].pop().unwrap(); //~ ERROR unused closure that must be used + + let b = false; + || true; //~ ERROR unused closure that must be used + println!("{}", b); +} + +fn ignored() { + let _ = || {}; + let _ = || yield 42; +} + +fn main() { + unused(); + ignored(); +} |