Improve documentation

Author: JungPhilipp

clang-tools-extra/clang-tidy/cppcoreguidelines/UseEnumClassCheck.h

@@ -13,8 +13,8 @@
 
 namespace clang::tidy::cppcoreguidelines {
 
-/// Check for unscoped enums that are not contained in classes/structs.
-/// Suggest to use scoped enums (enum class) instead.
+/// Check for unscoped enums and suggest to use scoped enums (enum class).
+/// Optionally, ignore unscoped enums in classes via IgnoreUnscopedEnumsInClasses
 ///
 /// For the user-facing documentation see:
 /// http://clang.llvm.org/extra/clang-tidy/checks/cppcoreguidelines/use-enum-class.html

clang-tools-extra/docs/ReleaseNotes.rst

@@ -139,7 +139,7 @@ New checks
 - New :doc:`cppcoreguidelines-use-enum-class
   <clang-tidy/checks/cppcoreguidelines/use-enum-class>` check.
 
-  Finds plain non-class enum definitions that could use ``enum class``.
+  Finds plain non-class ``enum`` definitions that could use ``enum class``.
 
 New check aliases
 ^^^^^^^^^^^^^^^^^

clang-tools-extra/docs/clang-tidy/checks/cppcoreguidelines/use-enum-class.rst

@@ -3,11 +3,11 @@
 cppcoreguidelines-use-enum-class
 =============================
 
-Scoped enums (enum class) should be preferred over unscoped enums:
-https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Renum-class
+Finds plain non-class ``enum`` definitions that could use ``enum class``.
 
-Unscoped enums in classes are not reported since it is a well
-established pattern to limit the scope of plain enums.
+This check implements `Enum.3
+<https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Renum-class>`_
+from the C++ Core Guidelines."
 
 Example:
 
@@ -17,10 +17,15 @@ Example:
   enum class E {};  // OK
 
   struct S {
-      enum E {};    // OK, scope already limited
+      enum E {};    // use "enum class E {};" instead
+                    // OK with option IgnoreUnscopedEnumsInClasses
   };
 
   namespace N {
       enum E {};    // use "enum class E {};" instead
-                    // report since it is hard to detect how large the surrounding namespace is
   }
+
+
+.. option:: IgnoreUnscopedEnumsInClasses
+
+   When `true` (default is `false`), ignores unscoped ``enum`` declarations in classes.