CPP: Improve the Enums3 test.

Author: geoffw0

cpp/ql/test/library-tests/enums/enums/Enums3.expected

@@ -1,10 +1,10 @@
-| enums.cpp:3:6:3:8 | Day | false |
-| enums.cpp:4:6:4:9 | Day2 | false |
-| enums.cpp:5:6:5:9 | Flag | false |
-| enums.cpp:19:7:19:17 | myLocalEnum | false |
-| enums.cpp:27:8:27:19 | MyNestedEnum | false |
-| enums.ms.c:1:6:1:12 | numbers | false |
-| scoped.cpp:2:12:2:13 | E1 | true |
-| scoped.cpp:6:12:6:13 | E2 | true |
-| scoped.cpp:10:13:10:14 | E3 | true |
-| scoped.cpp:16:14:16:18 | State | true |
+| enums.cpp:3:6:3:8 | Day |  |
+| enums.cpp:4:6:4:9 | Day2 |  |
+| enums.cpp:5:6:5:9 | Flag |  |
+| enums.cpp:19:7:19:17 | myLocalEnum | LocalEnum |
+| enums.cpp:27:8:27:19 | MyNestedEnum | NestedEnum |
+| enums.ms.c:1:6:1:12 | numbers |  |
+| scoped.cpp:2:12:2:13 | E1 | ScopedEnum |
+| scoped.cpp:6:12:6:13 | E2 | ScopedEnum |
+| scoped.cpp:10:13:10:14 | E3 | ScopedEnum |
+| scoped.cpp:16:14:16:18 | State | NestedEnum, ScopedEnum |

cpp/ql/test/library-tests/enums/enums/Enums3.ql

@@ -1,6 +1,18 @@
 import cpp
 
-from Enum e, boolean isScoped
-where if e instanceof ScopedEnum then isScoped = true else isScoped = false
-select e, isScoped
+string describe(Enum e)
+{
+  (
+    e instanceof LocalEnum and
+    result = "LocalEnum"
+  ) or (
+    e instanceof NestedEnum and
+    result = "NestedEnum"
+  ) or (
+    e instanceof ScopedEnum and
+    result = "ScopedEnum"
+  )
+}
 
+from Enum e
+select e, concat(describe(e), ", ")