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+A type mismatched an associated type of a trait.
+
+Erroneous code example:
+
+```compile_fail,E0271
+trait Trait { type AssociatedType; }
+
+fn foo<T>(t: T) where T: Trait<AssociatedType=u32> {
+//                    ~~~~~~~~ ~~~~~~~~~~~~~~~~~~
+//                        |            |
+//         This says `foo` can         |
+//           only be used with         |
+//              some type that         |
+//         implements `Trait`.         |
+//                                     |
+//                             This says not only must
+//                             `T` be an impl of `Trait`
+//                             but also that the impl
+//                             must assign the type `u32`
+//                             to the associated type.
+    println!("in foo");
+}
+
+impl Trait for i8 { type AssociatedType = &'static str; }
+//~~~~~~~~~~~~~~~   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//      |                             |
+// `i8` does have                     |
+// implementation                     |
+// of `Trait`...                      |
+//                     ... but it is an implementation
+//                     that assigns `&'static str` to
+//                     the associated type.
+
+foo(3_i8);
+// Here, we invoke `foo` with an `i8`, which does not satisfy
+// the constraint `<i8 as Trait>::AssociatedType=u32`, and
+// therefore the type-checker complains with this error code.
+```
+
+The issue can be resolved by changing the associated type:
+1) in the `foo` implementation:
+```
+trait Trait { type AssociatedType; }
+
+fn foo<T>(t: T) where T: Trait<AssociatedType = &'static str> {
+    println!("in foo");
+}
+
+impl Trait for i8 { type AssociatedType = &'static str; }
+
+foo(3_i8);
+```
+
+2) in the `Trait` implementation for `i8`:
+```
+trait Trait { type AssociatedType; }
+
+fn foo<T>(t: T) where T: Trait<AssociatedType = u32> {
+    println!("in foo");
+}
+
+impl Trait for i8 { type AssociatedType = u32; }
+
+foo(3_i8);
+```