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+An associated constant whose name does not match any of the associated constants
+in the trait was used when implementing the trait.
+
+Erroneous code example:
+
+```compile_fail,E0438
+trait Foo {}
+
+impl Foo for i32 {
+    const BAR: bool = true;
+}
+```
+
+Trait implementations can only implement associated constants that are
+members of the trait in question.
+
+The solution to this problem is to remove the extraneous associated constant:
+
+```
+trait Foo {}
+
+impl Foo for i32 {}
+```