You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and dots ('.'), can be up to 35 characters long. Letters must be lowercase.
106 lines
2.9 KiB
106 lines
2.9 KiB
// 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
|
|
|