Update documentation

cxx/include/enhanced_enum/enhanced_enum.hh

@@ -18,30 +18,34 @@ namespace enhanced_enum {
 
 /** \brief Base class for the enhanced enumeration types
  *
- * All essential functionality of an enhanced enum type is implemented
+ * The essential functionality of an enhanced enum type is implemented
  * in this class. A type gains the capabilities of an enhanced enum by
- * deriving from this class, and defining static constant array \c
- * values, as described in the user guide. The code for the derived
- * class is intended to be autogenerated to ensure conformance with
- * the requirements.
+ * deriving from this class, and defining a static constant array
+ * called \c values, as described in the user guide. The code for the
+ * derived class is intended to be autogenerated to ensure conformance
+ * with the requirements.
  *
- * There is order preserving isomorphism between the instances of \c
- * EnhancedEnum, and the enumerators of the underlying \c
+ * There is an order-preserving isomorphism between the instances of
+ * \c EnhancedEnum, and the enumerators of the underlying \c
  * LabelEnum. Thus, conceptually the instances of \c EnhancedEnum are
- * its enumerators, and will be called so in this class reference.
+ * its enumerators, and will be called so in the documentation.
  *
  * An enumerator of \c EnhancedEnum simply stores the value of its
  * label enumerator as its only member. Consequently, most of the
  * traits of \c LabelEnum are also traits of the \c EnhancedEnum type:
  * enhanced enumerations are regular, totally ordered, trivial, and
  * layout compatible with their underlying label enumerators.
  *
- * \note It is assumed that the definition of the derived class is
+ * It is assumed that the definition of the derived class is
  * compatible with the requirements imposed by the library. Most
  * notably the derived class must not have any non-static data members
- * or other non-empty base classes. The easiest way to ensure
+ * or other non-empty base classes. The intended way to ensure
  * compatibility is to autogenerate the definition.
  *
+ * \warning Trying to use an instance of a class derived from \ref
+ * enum_base not meeting the requirements imposed by the library
+ * results in undefined behavior.
+ *
  * \tparam EnhancedEnum The enhanced enumeration. The base class template
  * uses curiously recurring template pattern.
  * \tparam LabelEnum The underlying enumeration (<tt>enum class</tt>)
@@ -172,6 +176,8 @@ struct enum_base {
     }
 
     /** \brief Return the value of the enumerator
+     *
+     * \throw std::out_of_range if \c *this is not a valid enumerator
      */
     constexpr const value_type& value() const noexcept
     {
@@ -195,7 +201,7 @@ private:
  * \{
  */
 
-/** \brief Convert a label enumeration to the enhanced enumeration
+/** \brief Convert a label enumeration to an enhanced enumeration
  *
  * \tparam LabelEnum A label enum type (<tt>enum class</tt>)
  */