From d84f3edff5836cc5bcb2a991052248d82807815a Mon Sep 17 00:00:00 2001
From: "leonardo.yvens" <leoyvens@gmail.com>
Date: Wed, 29 Nov 2017 10:33:56 -0200
Subject: [PATCH] Test that trait definition owns the default, not the impl.

I don't know if it's what we want but it's how it works now. If we want
to keep it then we should forbid writing the default in the impl.
---
 .../trait_def_rules_over_impl.rs              | 31 +++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 src/test/run-pass/default-ty-param-fallback/trait_def_rules_over_impl.rs

diff --git a/src/test/run-pass/default-ty-param-fallback/trait_def_rules_over_impl.rs b/src/test/run-pass/default-ty-param-fallback/trait_def_rules_over_impl.rs
new file mode 100644
index 0000000000000..4bcf7a1176848
--- /dev/null
+++ b/src/test/run-pass/default-ty-param-fallback/trait_def_rules_over_impl.rs
@@ -0,0 +1,31 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(default_type_parameter_fallback)]
+
+trait Bar {
+    // Current we consider only the default in the trait,
+    // never the one in the impl.
+    // Is this good? Is it bad? Is it just the way it works?
+    // If this is ok then we should forbid writing the default in the impl.
+    fn method<A:Default=String>(&self) -> A;
+}
+
+struct Foo;
+
+impl Bar for Foo {
+    fn method<A:Default>(&self) -> A {
+        A::default()
+    }
+}
+
+fn main() {
+    Foo.method();
+}