--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/epoc32/include/stdapis/boost/smart_cast.hpp Tue Mar 16 16:12:26 2010 +0000
@@ -0,0 +1,298 @@
+#ifndef BOOST_SMART_CAST_HPP
+#define BOOST_SMART_CAST_HPP
+
+// MS compatible compilers support #pragma once
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+/////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
+// smart_cast.hpp:
+
+// (C) Copyright 2002 Robert Ramey - http://www.rrsd.com .
+// Use, modification and distribution is subject to the Boost Software
+// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+// See http://www.boost.org for updates, documentation, and revision history.
+
+// casting of pointers and references.
+
+// In casting between different C++ classes, there are a number of
+// rules that have to be kept in mind in deciding whether to use
+// static_cast or dynamic_cast.
+
+// a) dynamic casting can only be applied when one of the types is polymorphic
+// Otherwise static_cast must be used.
+// b) only dynamic casting can do runtime error checking
+// use of static_cast is generally un checked even when compiled for debug
+// c) static_cast would be considered faster than dynamic_cast.
+
+// If casting is applied to a template parameter, there is no apriori way
+// to know which of the two casting methods will be permitted or convenient.
+
+// smart_cast uses C++ type_traits, and program debug mode to select the
+// most convenient cast to use.
+
+#include <exception>
+#include <typeinfo>
+
+#include <boost/config.hpp>
+#include <boost/static_assert.hpp>
+
+#include <boost/type_traits/is_base_and_derived.hpp>
+#include <boost/type_traits/is_polymorphic.hpp>
+#include <boost/type_traits/is_pointer.hpp>
+#include <boost/type_traits/is_reference.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/type_traits/remove_pointer.hpp>
+#include <boost/type_traits/remove_reference.hpp>
+
+#include <boost/mpl/eval_if.hpp>
+#include <boost/mpl/if.hpp>
+#include <boost/mpl/or.hpp>
+#include <boost/mpl/and.hpp>
+#include <boost/mpl/not.hpp>
+#include <boost/mpl/identity.hpp>
+
+namespace boost {
+namespace smart_cast_impl {
+
+ template<class T>
+ struct reference {
+
+ struct polymorphic {
+
+ struct linear {
+ template<class U>
+ static T cast(U & u){
+ return static_cast<T>(u);
+ }
+ };
+
+ struct cross {
+ template<class U>
+ static T cast(U & u){
+ return dynamic_cast<T>(u);
+ }
+ };
+
+ template<class U>
+ static T cast(U & u){
+ // if we're in debug mode
+ #if ! defined(NDEBUG) \
+ || defined(__BORLANDC__) && (__BORLANDC__ <= 0x560) \
+ || defined(__MWERKS__)
+ // do a checked dynamic cast
+ return cross::cast(u);
+ #else
+ // borland 5.51 chokes here so we can't use it
+ // note: if remove_reference isn't function for these types
+ // cross casting will be selected this will work but will
+ // not be the most efficient method. This will conflict with
+ // the original smart_cast motivation.
+ typedef BOOST_DEDUCED_TYPENAME mpl::eval_if<
+ BOOST_DEDUCED_TYPENAME mpl::and_<
+ mpl::not_<is_base_and_derived<
+ BOOST_DEDUCED_TYPENAME remove_reference<T>::type,
+ U
+ > >,
+ mpl::not_<is_base_and_derived<
+ U,
+ BOOST_DEDUCED_TYPENAME remove_reference<T>::type
+ > >
+ >,
+ // borland chokes w/o full qualification here
+ mpl::identity<cross>,
+ mpl::identity<linear>
+ >::type typex;
+ // typex works around gcc 2.95 issue
+ return typex::cast(u);
+ #endif
+ }
+ };
+
+ struct non_polymorphic {
+ template<class U>
+ static T cast(U & u){
+ return static_cast<T>(u);
+ }
+ };
+ template<class U>
+ static T cast(U & u){
+ #if defined(__BORLANDC__)
+ return mpl::eval_if<
+ boost::is_polymorphic<U>,
+ mpl::identity<polymorphic>,
+ mpl::identity<non_polymorphic>
+ >::type::cast(u);
+ #else
+ typedef BOOST_DEDUCED_TYPENAME mpl::eval_if<
+ boost::is_polymorphic<U>,
+ mpl::identity<polymorphic>,
+ mpl::identity<non_polymorphic>
+ >::type typex;
+ return typex::cast(u);
+ #endif
+ }
+ };
+
+ template<class T>
+ struct pointer {
+
+ struct polymorphic {
+ // unfortunately, this below fails to work for virtual base
+ // classes. need has_virtual_base to do this.
+ // Subject for further study
+ #if 0
+ struct linear {
+ template<class U>
+ static T cast(U * u){
+ return static_cast<T>(u);
+ }
+ };
+
+ struct cross {
+ template<class U>
+ static T cast(U * u){
+ T tmp = dynamic_cast<T>(u);
+ #ifndef NDEBUG
+ if ( tmp == 0 ) throw std::bad_cast();
+ #endif
+ return tmp;
+ }
+ };
+
+ template<class U>
+ static T cast(U * u){
+ // if we're in debug mode
+ #if ! defined(NDEBUG) || defined(__BORLANDC__) && (__BORLANDC__ <= 0x560)
+ // do a checked dynamic cast
+ return cross::cast(u);
+ #else
+ // borland 5.51 chokes here so we can't use it
+ // note: if remove_pointer isn't function for these types
+ // cross casting will be selected this will work but will
+ // not be the most efficient method. This will conflict with
+ // the original smart_cast motivation.
+ typedef
+ BOOST_DEDUCED_TYPENAME mpl::eval_if<
+ BOOST_DEDUCED_TYPENAME mpl::and_<
+ mpl::not_<is_base_and_derived<
+ BOOST_DEDUCED_TYPENAME remove_pointer<T>::type,
+ U
+ > >,
+ mpl::not_<is_base_and_derived<
+ U,
+ BOOST_DEDUCED_TYPENAME remove_pointer<T>::type
+ > >
+ >,
+ // borland chokes w/o full qualification here
+ mpl::identity<cross>,
+ mpl::identity<linear>
+ >::type typex;
+ return typex::cast(u);
+ #endif
+ }
+ #else
+ template<class U>
+ static T cast(U * u){
+ T tmp = dynamic_cast<T>(u);
+ #ifndef NDEBUG
+ if ( tmp == 0 ) throw std::bad_cast();
+ #endif
+ return tmp;
+ }
+ #endif
+ };
+
+ struct non_polymorphic {
+ template<class U>
+ static T cast(U * u){
+ return static_cast<T>(u);
+ }
+ };
+
+ template<class U>
+ static T cast(U * u){
+ #if defined(__BORLANDC__)
+ return mpl::eval_if<
+ boost::is_polymorphic<U>,
+ mpl::identity<polymorphic>,
+ mpl::identity<non_polymorphic>
+ >::type::cast(u);
+ #else
+ typedef BOOST_DEDUCED_TYPENAME mpl::eval_if<
+ boost::is_polymorphic<U>,
+ mpl::identity<polymorphic>,
+ mpl::identity<non_polymorphic>
+ >::type typex;
+ return typex::cast(u);
+ #endif
+ }
+
+ };
+
+ template<class TPtr>
+ struct void_pointer {
+ template<class UPtr>
+ static TPtr cast(UPtr uptr){
+ return static_cast<TPtr>(uptr);
+ }
+ };
+
+ template<class T>
+ struct error {
+ // if we get here, its because we are using one argument in the
+ // cast on a system which doesn't support partial template
+ // specialization
+ template<class U>
+ static T cast(U u){
+ BOOST_STATIC_ASSERT(sizeof(T)==0);
+ return * static_cast<T *>(NULL);
+ }
+ };
+
+} // smart_cast_impl
+
+// this implements:
+// smart_cast<Target *, Source *>(Source * s)
+// smart_cast<Target &, Source &>(s)
+// note that it will fail with
+// smart_cast<Target &>(s)
+template<class T, class U>
+T smart_cast(U u) {
+ typedef
+ BOOST_DEDUCED_TYPENAME mpl::eval_if<
+ BOOST_DEDUCED_TYPENAME mpl::or_<
+ boost::is_same<void *, U>,
+ boost::is_same<void *, T>,
+ boost::is_same<const void *, U>,
+ boost::is_same<const void *, T>
+ >,
+ mpl::identity<smart_cast_impl::void_pointer<T> >,
+ // else
+ BOOST_DEDUCED_TYPENAME mpl::eval_if<boost::is_pointer<U>,
+ mpl::identity<smart_cast_impl::pointer<T> >,
+ // else
+ BOOST_DEDUCED_TYPENAME mpl::eval_if<boost::is_reference<U>,
+ mpl::identity<smart_cast_impl::reference<T> >,
+ // else
+ mpl::identity<smart_cast_impl::error<T>
+ >
+ >
+ >
+ >::type typex;
+ return typex::cast(u);
+}
+
+// this implements:
+// smart_cast_reference<Target &>(Source & s)
+template<class T, class U>
+T smart_cast_reference(U & u) {
+ return smart_cast_impl::reference<T>::cast(u);
+}
+
+} // namespace boost
+
+#endif // BOOST_SMART_CAST_HPP