Rollup merge of #109034 - compiler-errors:lazy-norm-tests, r=jackh726

Commit some tests for the new solver + lazy norm

Also consolidate `typeck/lazy-norm` into `traits/new-solver`, since it's not really useful to maintain a distinction, like when a test really is due to "lazy norm" or "the new solver" (usually both!)

Author: matthiaskrgr

tests/ui/typeck/lazy-norm/cast-checks-handling-projections.rs renamed to tests/ui/traits/new-solver/cast-checks-handling-projections.rs

@@ -0,0 +1,13 @@
+// check-pass
+// compile-flags: -Ztrait-solver=next
+// Issue 94358
+
+fn foo<C>(_: C)
+where
+    for <'a> &'a C: IntoIterator,
+    for <'a> <&'a C as IntoIterator>::IntoIter: ExactSizeIterator,
+{}
+
+fn main() {
+    foo::<_>(vec![true, false]);
+}

tests/ui/typeck/lazy-norm/equating-projection-cyclically.rs renamed to tests/ui/traits/new-solver/equating-projection-cyclically.rs

@@ -0,0 +1,23 @@
+// check-pass
+// compile-flags: -Ztrait-solver=next
+// Issue 95863
+
+pub trait With {
+    type F;
+}
+
+impl With for i32 {
+    type F = fn(&str);
+}
+
+fn f(_: &str) {}
+
+fn main() {
+    let _: V<i32> = V(f);
+    pub struct V<T: With>(<T as With>::F);
+
+    pub enum E3<T: With> {
+        Var(<T as With>::F),
+    }
+    let _: E3<i32> = E3::Var(f);
+}

tests/ui/typeck/lazy-norm/equating-projection-cyclically.stderr renamed to tests/ui/traits/new-solver/equating-projection-cyclically.stderr

@@ -0,0 +1,38 @@
+// check-pass
+// compile-flags: -Ztrait-solver=next
+// Issue 96750
+
+use std::marker::PhantomData;
+
+trait AsyncFn<Arg> {
+    type Output;
+}
+trait RequestFamily {
+    type Type<'a>;
+}
+trait Service {}
+
+struct MyFn;
+impl AsyncFn<String> for MyFn {
+    type Output = ();
+}
+
+impl RequestFamily for String {
+    type Type<'a> = String;
+}
+
+struct ServiceFromAsyncFn<F, Req>(F, PhantomData<Req>);
+
+impl<F, Req, O> Service for ServiceFromAsyncFn<F, Req>
+where
+    Req: RequestFamily,
+    F: AsyncFn<Req>,
+    F: for<'a> AsyncFn<Req::Type<'a>, Output = O>,
+{
+}
+
+fn assert_service() -> impl Service {
+    ServiceFromAsyncFn(MyFn, PhantomData)
+}
+
+fn main() {}

tests/ui/traits/new-solver/lazy-nested-obligations-1.rs

@@ -0,0 +1,40 @@
+// check-pass
+// compile-flags: -Ztrait-solver=next
+// Issue 108933
+
+trait Add<Rhs> {
+    type Sum;
+}
+
+impl Add<()> for () {
+    type Sum = ();
+}
+
+type Unit = <() as Add<()>>::Sum;
+
+trait Trait<C> {
+    type Output;
+}
+
+fn f<T>()
+where
+    T: Trait<()>,
+    <T as Trait<()>>::Output: Sized,
+{
+}
+
+fn g<T>()
+where
+    T: Trait<Unit>,
+    <T as Trait<()>>::Output: Sized,
+{
+}
+
+fn h<T>()
+where
+    T: Trait<()>,
+    <T as Trait<Unit>>::Output: Sized,
+{
+}
+
+fn main() {}

tests/ui/traits/new-solver/lazy-nested-obligations-2.rs

@@ -0,0 +1,26 @@
+// check-pass
+// compile-flags: -Ztrait-solver=next
+// Issue 92505
+
+trait A<T> {
+    type I;
+
+    fn f()
+    where
+        Self::I: A<T>,
+    {
+    }
+}
+
+impl<T> A<T> for () {
+    type I = ();
+
+    fn f()
+    where
+        Self::I: A<T>,
+    {
+        <() as A<T>>::f();
+    }
+}
+
+fn main() {}

tests/ui/traits/new-solver/lazy-nested-obligations-3.rs

@@ -0,0 +1,32 @@
+// check-pass
+// compile-flags: -Ztrait-solver=next
+// Issue 100177
+
+trait GenericTrait<T> {}
+
+trait Channel<I>: GenericTrait<Self::T> {
+    type T;
+}
+
+trait Sender {
+    type Msg;
+
+    fn send<C>()
+    where
+        C: Channel<Self::Msg>;
+}
+
+impl<T> Sender for T {
+    type Msg = ();
+
+    fn send<C>()
+    where
+        C: Channel<Self::Msg>,
+    {
+    }
+}
+
+// This works
+fn foo<I, C>(ch: C) where C: Channel<I> {}
+
+fn main() {}