107 lines
2.9 KiB
C++
107 lines
2.9 KiB
C++
|
// Copyright David Abrahams 2002.
|
||
|
|
// Distributed under 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)
|
||
|
|
#ifndef CAST_DWA200269_HPP
|
||
|
|
# define CAST_DWA200269_HPP
|
||
|
|
|
||
|
|
# include <boost/python/detail/prefix.hpp>
|
||
|
|
|
||
|
|
# include <boost/type_traits/same_traits.hpp>
|
||
|
|
# include <boost/type_traits/cv_traits.hpp>
|
||
|
|
# include <boost/type.hpp>
|
||
|
|
# include <boost/python/base_type_traits.hpp>
|
||
|
|
# include <boost/python/detail/convertible.hpp>
|
||
|
|
|
||
|
|
namespace boost { namespace python {
|
||
|
|
|
||
|
|
namespace detail
|
||
|
|
{
|
||
|
|
template <class Source, class Target> inline Target* upcast_impl(Source*, Target*);
|
||
|
|
|
||
|
|
template <class Source, class Target>
|
||
|
|
inline Target* upcast(Source* p, yes_convertible, no_convertible, Target*)
|
||
|
|
{
|
||
|
|
return p;
|
||
|
|
}
|
||
|
|
|
||
|
|
template <class Source, class Target>
|
||
|
|
inline Target* upcast(Source* p, no_convertible, no_convertible, Target*)
|
||
|
|
{
|
||
|
|
typedef typename base_type_traits<Source>::type base;
|
||
|
|
|
||
|
|
return detail::upcast_impl((base*)p, (Target*)0);
|
||
|
|
}
|
||
|
|
|
||
|
|
template <bool is_same = true>
|
||
|
|
struct upcaster
|
||
|
|
{
|
||
|
|
template <class T>
|
||
|
|
static inline T* execute(T* x, T*) { return x; }
|
||
|
|
};
|
||
|
|
|
||
|
|
template <>
|
||
|
|
struct upcaster<false>
|
||
|
|
{
|
||
|
|
template <class Source, class Target>
|
||
|
|
static inline Target* execute(Source* x, Target*)
|
||
|
|
{
|
||
|
|
return detail::upcast(
|
||
|
|
x, detail::convertible<Target*>::check(x)
|
||
|
|
, detail::convertible<Source*>::check((Target*)0)
|
||
|
|
, (Target*)0);
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
|
||
|
|
template <class Target, class Source>
|
||
|
|
inline Target* downcast(Source* p, yes_convertible)
|
||
|
|
{
|
||
|
|
return static_cast<Target*>(p);
|
||
|
|
}
|
||
|
|
|
||
|
|
template <class Target, class Source>
|
||
|
|
inline Target* downcast(Source* p, no_convertible, boost::type<Target>* = 0)
|
||
|
|
{
|
||
|
|
typedef typename base_type_traits<Source>::type base;
|
||
|
|
return (Target*)detail::downcast<base>(p, convertible<Source*>::check((base*)0));
|
||
|
|
}
|
||
|
|
|
||
|
|
template <class T>
|
||
|
|
inline void assert_castable(boost::type<T>* = 0)
|
||
|
|
{
|
||
|
|
typedef char must_be_a_complete_type[sizeof(T)];
|
||
|
|
}
|
||
|
|
|
||
|
|
template <class Source, class Target>
|
||
|
|
inline Target* upcast_impl(Source* x, Target*)
|
||
|
|
{
|
||
|
|
typedef typename add_cv<Source>::type src_t;
|
||
|
|
typedef typename add_cv<Target>::type target_t;
|
||
|
|
bool const same = is_same<src_t,target_t>::value;
|
||
|
|
|
||
|
|
return detail::upcaster<same>::execute(x, (Target*)0);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
template <class Target, class Source>
|
||
|
|
inline Target* upcast(Source* x, Target* = 0)
|
||
|
|
{
|
||
|
|
detail::assert_castable<Source>();
|
||
|
|
detail::assert_castable<Target>();
|
||
|
|
return detail::upcast_impl(x, (Target*)0);
|
||
|
|
|
||
|
|
}
|
||
|
|
|
||
|
|
template <class Target, class Source>
|
||
|
|
inline Target* downcast(Source* x, Target* = 0)
|
||
|
|
{
|
||
|
|
detail::assert_castable<Source>();
|
||
|
|
detail::assert_castable<Target>();
|
||
|
|
return detail::downcast<Target>(x, detail::convertible<Source*>::check((Target*)0));
|
||
|
|
}
|
||
|
|
|
||
|
|
}} // namespace boost::python
|
||
|
|
|
||
|
|
#endif // CAST_DWA200269_HPP
|