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

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

diff --git a/src/tools/clippy/tests/ui/mem_replace.rs b/src/tools/clippy/tests/ui/mem_replace.rs
new file mode 100644 (file)
index 0000000..60f5278
--- /dev/null
+++ b/src/tools/clippy/tests/ui/mem_replace.rs
@@ -0,0 +1,30 @@
+// run-rustfix
+#![allow(unused_imports)]
+#![warn(
+    clippy::all,
+    clippy::style,
+    clippy::mem_replace_option_with_none,
+    clippy::mem_replace_with_default
+)]
+
+use std::mem;
+
+fn replace_option_with_none() {
+    let mut an_option = Some(1);
+    let _ = mem::replace(&mut an_option, None);
+    let an_option = &mut Some(1);
+    let _ = mem::replace(an_option, None);
+}
+
+fn replace_with_default() {
+    let mut s = String::from("foo");
+    let _ = std::mem::replace(&mut s, String::default());
+    let s = &mut String::from("foo");
+    let _ = std::mem::replace(s, String::default());
+    let _ = std::mem::replace(s, Default::default());
+}
+
+fn main() {
+    replace_option_with_none();
+    replace_with_default();
+}