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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
commit698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch)
tree173a775858bd501c378080a10dca74132f05bc50 /src/tools/clippy/tests/ui/useless_conversion.rs
parentInitial commit. (diff)
downloadrustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz
rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/tools/clippy/tests/ui/useless_conversion.rs')
-rw-r--r--src/tools/clippy/tests/ui/useless_conversion.rs92
1 files changed, 92 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/useless_conversion.rs b/src/tools/clippy/tests/ui/useless_conversion.rs
new file mode 100644
index 000000000..f2444a8f4
--- /dev/null
+++ b/src/tools/clippy/tests/ui/useless_conversion.rs
@@ -0,0 +1,92 @@
+// run-rustfix
+
+#![deny(clippy::useless_conversion)]
+#![allow(clippy::unnecessary_wraps)]
+
+fn test_generic<T: Copy>(val: T) -> T {
+ let _ = T::from(val);
+ val.into()
+}
+
+fn test_generic2<T: Copy + Into<i32> + Into<U>, U: From<T>>(val: T) {
+ // ok
+ let _: i32 = val.into();
+ let _: U = val.into();
+ let _ = U::from(val);
+}
+
+fn test_questionmark() -> Result<(), ()> {
+ {
+ let _: i32 = 0i32.into();
+ Ok(Ok(()))
+ }??;
+ Ok(())
+}
+
+fn test_issue_3913() -> Result<(), std::io::Error> {
+ use std::fs;
+ use std::path::Path;
+
+ let path = Path::new(".");
+ for _ in fs::read_dir(path)? {}
+
+ Ok(())
+}
+
+fn test_issue_5833() -> Result<(), ()> {
+ let text = "foo\r\nbar\n\nbaz\n";
+ let lines = text.lines();
+ if Some("ok") == lines.into_iter().next() {}
+
+ Ok(())
+}
+
+fn main() {
+ test_generic(10i32);
+ test_generic2::<i32, i32>(10i32);
+ test_questionmark().unwrap();
+ test_issue_3913().unwrap();
+ test_issue_5833().unwrap();
+
+ let _: String = "foo".into();
+ let _: String = From::from("foo");
+ let _ = String::from("foo");
+ #[allow(clippy::useless_conversion)]
+ {
+ let _: String = "foo".into();
+ let _ = String::from("foo");
+ let _ = "".lines().into_iter();
+ }
+
+ let _: String = "foo".to_string().into();
+ let _: String = From::from("foo".to_string());
+ let _ = String::from("foo".to_string());
+ let _ = String::from(format!("A: {:04}", 123));
+ let _ = "".lines().into_iter();
+ let _ = vec![1, 2, 3].into_iter().into_iter();
+ let _: String = format!("Hello {}", "world").into();
+
+ // keep parentheses around `a + b` for suggestion (see #4750)
+ let a: i32 = 1;
+ let b: i32 = 1;
+ let _ = i32::from(a + b) * 3;
+
+ // see #7205
+ let s: Foo<'a'> = Foo;
+ let _: Foo<'b'> = s.into();
+ let s2: Foo<'a'> = Foo;
+ let _: Foo<'a'> = s2.into();
+ let s3: Foo<'a'> = Foo;
+ let _ = Foo::<'a'>::from(s3);
+ let s4: Foo<'a'> = Foo;
+ let _ = vec![s4, s4, s4].into_iter().into_iter();
+}
+
+#[derive(Copy, Clone)]
+struct Foo<const C: char>;
+
+impl From<Foo<'a'>> for Foo<'b'> {
+ fn from(_s: Foo<'a'>) -> Self {
+ Foo
+ }
+}