diff options
Diffstat (limited to 'boost/type_index/runtime_cast/register_runtime_class.hpp')
| -rw-r--r-- | boost/type_index/runtime_cast/register_runtime_class.hpp | 62 |
1 files changed, 56 insertions, 6 deletions
diff --git a/boost/type_index/runtime_cast/register_runtime_class.hpp b/boost/type_index/runtime_cast/register_runtime_class.hpp index 37ce686e32..995007487b 100644 --- a/boost/type_index/runtime_cast/register_runtime_class.hpp +++ b/boost/type_index/runtime_cast/register_runtime_class.hpp @@ -10,7 +10,8 @@ #define BOOST_TYPE_INDEX_RUNTIME_CAST_REGISTER_RUNTIME_CLASS_HPP /// \file register_runtime_class.hpp -/// \brief Contains the macro BOOST_TYPE_INDEX_REGISTER_RUNTIME_CLASS +/// \brief Contains the macros BOOST_TYPE_INDEX_IMPLEMENT_RUNTIME_CAST and +/// BOOST_TYPE_INDEX_REGISTER_RUNTIME_CLASS #include <boost/type_index.hpp> #include <boost/preprocessor/seq/for_each.hpp> @@ -29,6 +30,8 @@ inline type_index runtime_class_construct_type_id(T const*) { } // namespace detail +}} // namespace boost::typeindex + /// @cond #define BOOST_TYPE_INDEX_CHECK_BASE_(r, data, Base) \ @@ -44,6 +47,11 @@ inline type_index runtime_class_construct_type_id(T const*) { /// boost::typeindex::runtime_cast to accurately convert between dynamic types of instances of /// the current class. /// +/// BOOST_TYPE_INDEX_REGISTER_RUNTIME_CLASS also adds support for boost::typeindex::type_id_runtime +/// by including BOOST_TYPE_INDEX_REGISTER_CLASS. It is typical that these features are used together, +/// but in the event that BOOST_TYPE_INDEX_REGISTER_CLASS is undesirable in the current class, +/// BOOST_TYPE_INDEX_IMPLEMENT_RUNTIME_CAST is provided. +/// /// \b Example: /// \code /// struct base1 { @@ -67,22 +75,64 @@ inline type_index runtime_class_construct_type_id(T const*) { /// ... /// /// base1* pb1 = get_object(); -/// if(derived2* pb2 = boost::typeindex::runtime_cast<derived2*>(pb1)) -/// { /* ... */ } +/// if(derived2* pb2 = boost::typeindex::runtime_cast<derived2*>(pb1)) { +/// assert(boost::typeindex::type_id_runtime(*pb1)) == boost::typeindex::type_id<derived2>()); +/// } /// \endcode /// /// \param base_class_seq A Boost.Preprocessor sequence of the current class' direct bases, or -/// BOOST_PP_SEQ_NIL if this class has no direct base classes. +/// BOOST_TYPE_INDEX_NO_BASE_CLASS if this class has no direct base classes. #define BOOST_TYPE_INDEX_REGISTER_RUNTIME_CLASS(base_class_seq) \ - BOOST_TYPE_INDEX_REGISTER_CLASS \ + BOOST_TYPE_INDEX_REGISTER_CLASS \ + BOOST_TYPE_INDEX_IMPLEMENT_RUNTIME_CAST(base_class_seq) + +/// \def BOOST_TYPE_INDEX_IMPLEMENT_RUNTIME_CAST +/// \brief Macro used to make a class compatible with boost::typeindex::runtime_cast without including +/// support for boost::typeindex::type_id_runtime. +/// +/// BOOST_TYPE_INDEX_IMPLEMENT_RUNTIME_CAST is provided as an alternative to BOOST_TYPE_INDEX_REGISTER_RUNTIME_CLASS +/// in the event that support for boost::typeindex::type_id_runtime is undesirable. +/// +/// \b Example: +/// \code +/// struct base1 { +/// BOOST_TYPE_INDEX_IMPLEMENT_RUNTIME_CAST(BOOST_TYPE_INDEX_NO_BASE_CLASS) +/// virtual ~base1(); +/// }; +/// +/// struct base2 { +/// BOOST_TYPE_INDEX_IMPLEMENT_RUNTIME_CAST(BOOST_TYPE_INDEX_NO_BASE_CLASS) +/// virtual ~base2(); +/// }; +/// +/// struct derived1 : base1 { +/// BOOST_TYPE_INDEX_IMPLEMENT_RUNTIME_CAST((base1)) +/// }; +/// +/// struct derived2 : base1, base2 { +/// BOOST_TYPE_INDEX_IMPLEMENT_RUNTIME_CAST((base1)(base2)) +/// }; +/// +/// ... +/// +/// base1* pb1 = get_object(); +/// if(derived2* pb2 = boost::typeindex::runtime_cast<derived2*>(pb1)) +/// { /* can't call boost::typeindex::type_id_runtime(*pb1) here */ } +/// \endcode +/// +/// \param base_class_seq A Boost.Preprocessor sequence of the current class' direct bases, or +/// BOOST_TYPE_INDEX_NO_BASE_CLASS if this class has no direct base classes. +#define BOOST_TYPE_INDEX_IMPLEMENT_RUNTIME_CAST(base_class_seq) \ virtual void const* boost_type_index_find_instance_(boost::typeindex::type_index const& idx) const BOOST_NOEXCEPT { \ if(idx == boost::typeindex::detail::runtime_class_construct_type_id(this)) \ return this; \ BOOST_PP_SEQ_FOR_EACH(BOOST_TYPE_INDEX_CHECK_BASE_, _, base_class_seq) \ return NULL; \ } -}} // namespace boost::typeindex +/// \def BOOST_TYPE_INDEX_NO_BASE_CLASS +/// \brief Instructs BOOST_TYPE_INDEX_REGISTER_RUNTIME_CLASS and BOOST_TYPE_INDEX_IMPLEMENT_RUNTIME_CAST +/// that this class has no base classes. #define BOOST_TYPE_INDEX_NO_BASE_CLASS BOOST_PP_SEQ_NIL #endif // BOOST_TYPE_INDEX_RUNTIME_CAST_REGISTER_RUNTIME_CLASS_HPP |