mirror of https://github.com/axmolengine/axmol.git
47 lines
1.5 KiB
C++
47 lines
1.5 KiB
C++
|
// (C) Copyright Kevlin Henney and Dave Abrahams 1999.
|
||
|
|
// 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 RANGES_V3_UTILITY_POLYMORPHIC_CAST_HPP
|
||
|
|
#define RANGES_V3_UTILITY_POLYMORPHIC_CAST_HPP
|
||
|
|
|
||
|
|
#include <memory>
|
||
|
|
#include <type_traits>
|
||
|
|
|
||
|
|
#include <meta/meta.hpp>
|
||
|
|
|
||
|
|
#include <range/v3/detail/config.hpp>
|
||
|
|
|
||
|
|
#include <range/v3/detail/prologue.hpp>
|
||
|
|
|
||
|
|
namespace ranges
|
||
|
|
{
|
||
|
|
template<typename Target, typename Source>
|
||
|
|
auto polymorphic_downcast(Source * x) noexcept
|
||
|
|
-> meta::if_<std::is_pointer<Target>,
|
||
|
|
decltype((static_cast<Target>(x), dynamic_cast<Target>(x)))>
|
||
|
|
{
|
||
|
|
auto result = static_cast<Target>(x);
|
||
|
|
RANGES_ASSERT(dynamic_cast<Target>(x) == result);
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
template<typename Target, typename Source>
|
||
|
|
auto polymorphic_downcast(Source && x) noexcept
|
||
|
|
-> meta::if_<std::is_reference<Target>,
|
||
|
|
decltype((static_cast<Target>(std::declval<Source>()),
|
||
|
|
dynamic_cast<Target>(std::declval<Source>())))>
|
||
|
|
{
|
||
|
|
auto && result = static_cast<Target>(static_cast<Source &&>(x));
|
||
|
|
#ifndef NDEBUG
|
||
|
|
auto && dresult = dynamic_cast<Target>(static_cast<Source &&>(x));
|
||
|
|
RANGES_ASSERT(std::addressof(dresult) == std::addressof(result));
|
||
|
|
#endif
|
||
|
|
return static_cast<Target>(result);
|
||
|
|
}
|
||
|
|
} // namespace ranges
|
||
|
|
|
||
|
|
#include <range/v3/detail/epilogue.hpp>
|
||
|
|
|
||
|
|
#endif // RANGES_V3_UTILITY_POLYMORPHIC_CAST_HPP
|