1 files changed, 26 insertions, 0 deletions
diff --git a/src/test/ui/coherence/coherence-fn-implied-bounds.rs b/src/test/ui/coherence/coherence-fn-implied-bounds.rs
new file mode 100644
index 000000000..4539af9a3
--- /dev/null
+++ b/src/test/ui/coherence/coherence-fn-implied-bounds.rs
@@ -0,0 +1,26 @@
+// Test that our leak-check is not smart enough to take implied bounds
+// into account (yet). Here we have two types that look like they
+// should not be equivalent, but because of the rules on implied
+// bounds we ought to know that, in fact, `'a = 'b` must always hold,
+// and hence they are.
+//
+// Rustc can't figure this out and hence it accepts the impls but
+// gives a future-compatibility warning (because we'd like to make
+// this an error someday).
+//
+// Note that while we would like to make this a hard error, we also
+// give the same warning for `coherence-wasm-bindgen.rs`, which ought
+// to be accepted.
+
+#![deny(coherence_leak_check)]
+
+trait Trait {}
+
+impl Trait for for<'a, 'b> fn(&'a &'b u32, &'b &'a u32) -> &'b u32 {}
+
+impl Trait for for<'c> fn(&'c &'c u32, &'c &'c u32) -> &'c u32 {
+    //~^ ERROR conflicting implementations
+    //~| WARNING this was previously accepted by the compiler
+}
+
+fn main() {}