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kicad/include/boost/serialization/smart_cast.hpp

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#ifndef BOOST_SERIALIZATION_SMART_CAST_HPP
#define BOOST_SERIALIZATION_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/libs/serialization 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 <cstddef> // NULL
#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 serialization {
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 serialization
} // namespace boost
#endif // BOOST_SERIALIZATION_SMART_CAST_HPP
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