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+An associated const has been referenced in a pattern.
+
+Erroneous code example:
+
+```compile_fail,E0158
+enum EFoo { A, B, C, D }
+
+trait Foo {
+    const X: EFoo;
+}
+
+fn test<A: Foo>(arg: EFoo) {
+    match arg {
+        A::X => { // error!
+            println!("A::X");
+        }
+    }
+}
+```
+
+`const` and `static` mean different things. A `const` is a compile-time
+constant, an alias for a literal value. This property means you can match it
+directly within a pattern.
+
+The `static` keyword, on the other hand, guarantees a fixed location in memory.
+This does not always mean that the value is constant. For example, a global
+mutex can be declared `static` as well.
+
+If you want to match against a `static`, consider using a guard instead:
+
+```
+static FORTY_TWO: i32 = 42;
+
+match Some(42) {
+    Some(x) if x == FORTY_TWO => {}
+    _ => {}
+}
+```