Update upstream source from tag 'upstream/1.52.1+dfsg1'

[rustc.git] / src / tools / clippy / tests / ui / mut_reference.rs

diff --git a/src/tools/clippy/tests/ui/mut_reference.rs b/src/tools/clippy/tests/ui/mut_reference.rs
new file mode 100644 (file)
index 0000000..7390612
--- /dev/null
+++ b/src/tools/clippy/tests/ui/mut_reference.rs
@@ -0,0 +1,43 @@
+#![allow(unused_variables)]
+
+fn takes_an_immutable_reference(a: &i32) {}
+fn takes_a_mutable_reference(a: &mut i32) {}
+
+struct MyStruct;
+
+impl MyStruct {
+    fn takes_an_immutable_reference(&self, a: &i32) {}
+
+    fn takes_a_mutable_reference(&self, a: &mut i32) {}
+}
+
+#[warn(clippy::unnecessary_mut_passed)]
+fn main() {
+    // Functions
+    takes_an_immutable_reference(&mut 42);
+    let as_ptr: fn(&i32) = takes_an_immutable_reference;
+    as_ptr(&mut 42);
+
+    // Methods
+    let my_struct = MyStruct;
+    my_struct.takes_an_immutable_reference(&mut 42);
+
+    // No error
+
+    // Functions
+    takes_an_immutable_reference(&42);
+    let as_ptr: fn(&i32) = takes_an_immutable_reference;
+    as_ptr(&42);
+
+    takes_a_mutable_reference(&mut 42);
+    let as_ptr: fn(&mut i32) = takes_a_mutable_reference;
+    as_ptr(&mut 42);
+
+    let a = &mut 42;
+    takes_an_immutable_reference(a);
+
+    // Methods
+    my_struct.takes_an_immutable_reference(&42);
+    my_struct.takes_a_mutable_reference(&mut 42);
+    my_struct.takes_an_immutable_reference(a);
+}