Organize trait test files

src/test/ui/traits/static-method-generic-inference.rs

@@ -0,0 +1,28 @@
+// Issue #3902. We are (at least currently) unable to infer `Self`
+// based on `T`, even though there is only a single impl, because of
+// the possibility of associated types and other things (basically: no
+// constraints on `Self` here at all).
+
+mod base {
+    pub trait HasNew<T> {
+        fn new() -> T;
+        fn dummy(&self) { }
+    }
+
+    pub struct Foo {
+        dummy: (),
+    }
+
+    impl HasNew<Foo> for Foo {
+        fn new() -> Foo {
+            Foo { dummy: () }
+        }
+    }
+}
+
+pub fn foo() {
+    let _f: base::Foo = base::HasNew::new();
+    //~^ ERROR type annotations needed
+}
+
+fn main() { }