diff options
Diffstat (limited to 'src/test/ui/lint/let_underscore')
4 files changed, 63 insertions, 0 deletions
diff --git a/src/test/ui/lint/let_underscore/let_underscore_drop.rs b/src/test/ui/lint/let_underscore/let_underscore_drop.rs new file mode 100644 index 000000000..f298871f1 --- /dev/null +++ b/src/test/ui/lint/let_underscore/let_underscore_drop.rs @@ -0,0 +1,14 @@ +// check-pass +#![warn(let_underscore_drop)] + +struct NontrivialDrop; + +impl Drop for NontrivialDrop { + fn drop(&mut self) { + println!("Dropping!"); + } +} + +fn main() { + let _ = NontrivialDrop; //~WARNING non-binding let on a type that implements `Drop` +} diff --git a/src/test/ui/lint/let_underscore/let_underscore_drop.stderr b/src/test/ui/lint/let_underscore/let_underscore_drop.stderr new file mode 100644 index 000000000..7b7de202e --- /dev/null +++ b/src/test/ui/lint/let_underscore/let_underscore_drop.stderr @@ -0,0 +1,22 @@ +warning: non-binding let on a type that implements `Drop` + --> $DIR/let_underscore_drop.rs:13:5 + | +LL | let _ = NontrivialDrop; + | ^^^^^^^^^^^^^^^^^^^^^^^ + | +note: the lint level is defined here + --> $DIR/let_underscore_drop.rs:2:9 + | +LL | #![warn(let_underscore_drop)] + | ^^^^^^^^^^^^^^^^^^^ +help: consider binding to an unused variable to avoid immediately dropping the value + | +LL | let _unused = NontrivialDrop; + | ~~~~~~~ +help: consider immediately dropping the value + | +LL | drop(NontrivialDrop); + | ~~~~~ + + +warning: 1 warning emitted + diff --git a/src/test/ui/lint/let_underscore/let_underscore_lock.rs b/src/test/ui/lint/let_underscore/let_underscore_lock.rs new file mode 100644 index 000000000..7423862cd --- /dev/null +++ b/src/test/ui/lint/let_underscore/let_underscore_lock.rs @@ -0,0 +1,7 @@ +// check-fail +use std::sync::{Arc, Mutex}; + +fn main() { + let data = Arc::new(Mutex::new(0)); + let _ = data.lock().unwrap(); //~ERROR non-binding let on a synchronization lock +} diff --git a/src/test/ui/lint/let_underscore/let_underscore_lock.stderr b/src/test/ui/lint/let_underscore/let_underscore_lock.stderr new file mode 100644 index 000000000..fb58af0a4 --- /dev/null +++ b/src/test/ui/lint/let_underscore/let_underscore_lock.stderr @@ -0,0 +1,20 @@ +error: non-binding let on a synchronization lock + --> $DIR/let_underscore_lock.rs:6:9 + | +LL | let _ = data.lock().unwrap(); + | ^ ^^^^^^^^^^^^^^^^^^^^ this binding will immediately drop the value assigned to it + | | + | this lock is not assigned to a binding and is immediately dropped + | + = note: `#[deny(let_underscore_lock)]` on by default +help: consider binding to an unused variable to avoid immediately dropping the value + | +LL | let _unused = data.lock().unwrap(); + | ~~~~~~~ +help: consider immediately dropping the value + | +LL | drop(data.lock().unwrap()); + | ~~~~~ + + +error: aborting due to previous error + |