Rollup merge of #147597 - JohnTitor:issue-72207, r=chenyukang

Add a regression test for #72207Closes#72207

Author: matthiaskrgr

tests/ui/impl-trait/associated-type-fn-bound-issue-72207.rs

@@ -0,0 +1,57 @@
+//@ check-pass
+//@ compile-flags: --crate-type=lib
+
+#![allow(dead_code)]
+
+use std::marker::PhantomData;
+
+pubstructXImpl<T,E,F2,F1>
+where
+F2:Fn(E),
+{
+f1:F1,
+f2:F2,
+_ghost:PhantomData<(T,E)>,
+}
+
+pubtraitX<T>:Sized{
+typeF1;
+typeF2:Fn(Self::E);
+typeE;
+
+fnand<NewF1,NewF1Generator>(self,f:NewF1Generator) -> XImpl<T,Self::E,Self::F2,NewF1>
+where
+NewF1Generator:FnOnce(Self::F1) -> NewF1;
+}
+
+impl<T,E,F2,F1>X<T>forXImpl<T,E,F2,F1>
+where
+F2:Fn(E),
+{
+typeE = E;
+typeF2 = F2;
+typeF1 = F1;
+
+fnand<NewF1,NewF1Generator>(self,f:NewF1Generator) -> XImpl<T,E,F2,NewF1>
+where
+NewF1Generator:FnOnce(F1) -> NewF1,
+{
+XImpl{
+f1:f(self.f1),
+f2:self.f2,
+_ghost:PhantomData,
+}
+}
+}
+
+fnf() -> implX<(),E = ()>{
+XImpl{
+f1: || (),
+f2: |()| (),
+_ghost:PhantomData,
+}
+}
+
+fnf2() -> implX<(),E = ()>{
+f().and(|rb| rb)
+}