Regression test for rust-lang#56870

Author: adrian-budau

src/test/ui/issues/issue-56870.rs

@@ -0,0 +1,38 @@
+// build-pass
+// Regression test for #56870: Internal compiler error (traits & associated consts)
+
+use std::fmt::Debug;
+
+pub trait Foo<T> {
+  const FOO: *const u8;
+}
+
+impl <T: Debug> Foo<T> for dyn Debug {
+  const FOO: *const u8 = <T as Debug>::fmt as *const u8;
+}
+
+pub trait Bar {
+  const BAR: *const u8;
+}
+
+pub trait Baz {
+  type Data: Debug;
+}
+
+pub struct BarStruct<S: Baz>(S);
+
+impl<S: Baz> Bar for BarStruct<S> {
+  const BAR: *const u8 = <dyn Debug as Foo<<S as Baz>::Data>>::FOO;
+}
+
+struct AnotherStruct;
+#[derive(Debug)]
+struct SomeStruct;
+
+impl Baz for AnotherStruct {
+  type Data = SomeStruct;
+}
+
+fn main() {
+  let _x = <BarStruct<AnotherStruct> as Bar>::BAR;
+}