1 files changed, 166 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/trait_duplication_in_bounds_unfixable.rs b/src/tools/clippy/tests/ui/trait_duplication_in_bounds_unfixable.rs
new file mode 100644
index 000000000..5630a0345
--- /dev/null
+++ b/src/tools/clippy/tests/ui/trait_duplication_in_bounds_unfixable.rs
@@ -0,0 +1,166 @@
+#![deny(clippy::trait_duplication_in_bounds)]
+
+use std::collections::BTreeMap;
+use std::ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Sub, SubAssign};
+
+fn bad_foo<T: Clone + Default, Z: Copy>(arg0: T, arg1: Z)
+where
+    T: Clone,
+    T: Default,
+{
+    unimplemented!();
+}
+
+fn good_bar<T: Clone + Default>(arg: T) {
+    unimplemented!();
+}
+
+fn good_foo<T>(arg: T)
+where
+    T: Clone + Default,
+{
+    unimplemented!();
+}
+
+fn good_foobar<T: Default>(arg: T)
+where
+    T: Clone,
+{
+    unimplemented!();
+}
+
+trait T: Default {
+    fn f()
+    where
+        Self: Default;
+}
+
+trait U: Default {
+    fn f()
+    where
+        Self: Clone;
+}
+
+trait ZZ: Default {
+    fn g();
+    fn h();
+    fn f()
+    where
+        Self: Default + Clone;
+}
+
+trait BadTrait: Default + Clone {
+    fn f()
+    where
+        Self: Default + Clone;
+    fn g()
+    where
+        Self: Default;
+    fn h()
+    where
+        Self: Copy;
+}
+
+#[derive(Default, Clone)]
+struct Life;
+
+impl T for Life {
+    // this should not warn
+    fn f() {}
+}
+
+impl U for Life {
+    // this should not warn
+    fn f() {}
+}
+
+// should not warn
+trait Iter: Iterator {
+    fn into_group_btreemap<K, V>(self) -> BTreeMap<K, Vec<V>>
+    where
+        Self: Iterator<Item = (K, V)> + Sized,
+        K: Ord + Eq,
+    {
+        unimplemented!();
+    }
+}
+
+struct Foo;
+
+trait FooIter: Iterator<Item = Foo> {
+    fn bar()
+    where
+        Self: Iterator<Item = Foo>,
+    {
+    }
+}
+
+// The below should not lint and exist to guard against false positives
+fn impl_trait(_: impl AsRef<str>, _: impl AsRef<str>) {}
+
+pub mod one {
+    #[derive(Clone, Debug)]
+    struct MultiProductIter<I>
+    where
+        I: Iterator + Clone,
+        I::Item: Clone,
+    {
+        _marker: I,
+    }
+
+    pub struct MultiProduct<I>(Vec<MultiProductIter<I>>)
+    where
+        I: Iterator + Clone,
+        I::Item: Clone;
+
+    pub fn multi_cartesian_product<H>(_: H) -> MultiProduct<<H::Item as IntoIterator>::IntoIter>
+    where
+        H: Iterator,
+        H::Item: IntoIterator,
+        <H::Item as IntoIterator>::IntoIter: Clone,
+        <H::Item as IntoIterator>::Item: Clone,
+    {
+        todo!()
+    }
+}
+
+pub mod two {
+    use std::iter::Peekable;
+
+    pub struct MergeBy<I, J, F>
+    where
+        I: Iterator,
+        J: Iterator<Item = I::Item>,
+    {
+        _i: Peekable<I>,
+        _j: Peekable<J>,
+        _f: F,
+    }
+
+    impl<I, J, F> Clone for MergeBy<I, J, F>
+    where
+        I: Iterator,
+        J: Iterator<Item = I::Item>,
+        std::iter::Peekable<I>: Clone,
+        std::iter::Peekable<J>: Clone,
+        F: Clone,
+    {
+        fn clone(&self) -> Self {
+            Self {
+                _i: self._i.clone(),
+                _j: self._j.clone(),
+                _f: self._f.clone(),
+            }
+        }
+    }
+}
+
+pub trait Trait {}
+
+pub fn f(_a: impl Trait, _b: impl Trait) {}
+
+pub trait ImplTrait<T> {}
+
+impl<A, B> ImplTrait<(A, B)> for Foo where Foo: ImplTrait<A> + ImplTrait<B> {}
+
+fn main() {}