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+// Copyright 2014 Renato Tegon Forti, Antony Polukhin.
+// Copyright 2015-2016 Antony Polukhin.
+//
+// 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 BOOST_DLL_DETAIL_AGGRESSIVE_PTR_CAST_HPP
+#define BOOST_DLL_DETAIL_AGGRESSIVE_PTR_CAST_HPP
+
+#include <boost/config.hpp>
+#ifdef BOOST_HAS_PRAGMA_ONCE
+# pragma once
+#endif
+
+#include <boost/static_assert.hpp>
+#include <boost/type_traits/is_pointer.hpp>
+#include <boost/type_traits/is_member_pointer.hpp>
+#include <boost/type_traits/is_void.hpp>
+#include <boost/type_traits/is_reference.hpp>
+#include <boost/type_traits/remove_pointer.hpp>
+#include <boost/type_traits/remove_reference.hpp>
+#include <boost/utility/enable_if.hpp>
+#include <boost/cstdint.hpp> // boost::uintptr_t
+#include <cstring> // std::memcpy
+
+namespace boost { namespace dll { namespace detail {
+
+// GCC warns when reinterpret_cast between function pointer and object pointer occur.
+// This method suppress the warnings and ensures that such casts are safe.
+template <class To, class From>
+BOOST_FORCEINLINE typename boost::disable_if_c<boost::is_member_pointer<To>::value || boost::is_reference<To>::value || boost::is_member_pointer<From>::value, To>::type
+ aggressive_ptr_cast(From v) BOOST_NOEXCEPT
+{
+ BOOST_STATIC_ASSERT_MSG(
+ boost::is_pointer<To>::value && boost::is_pointer<From>::value,
+ "`agressive_ptr_cast` function must be used only for pointer casting."
+ );
+
+ BOOST_STATIC_ASSERT_MSG(
+ boost::is_void< typename boost::remove_pointer<To>::type >::value
+ || boost::is_void< typename boost::remove_pointer<From>::type >::value,
+ "`agressive_ptr_cast` function must be used only for casting to or from void pointers."
+ );
+
+ BOOST_STATIC_ASSERT_MSG(
+ sizeof(v) == sizeof(To),
+ "Pointer to function and pointer to object differ in size on your platform."
+ );
+
+ return reinterpret_cast<To>(
+ reinterpret_cast<boost::uintptr_t>(v)
+ );
+}
+
+template <class To, class From>
+BOOST_FORCEINLINE typename boost::disable_if_c<!boost::is_reference<To>::value || boost::is_member_pointer<From>::value, To>::type
+ aggressive_ptr_cast(From v) BOOST_NOEXCEPT
+{
+ BOOST_STATIC_ASSERT_MSG(
+ boost::is_pointer<From>::value,
+ "`agressive_ptr_cast` function must be used only for pointer casting."
+ );
+
+ BOOST_STATIC_ASSERT_MSG(
+ boost::is_void< typename boost::remove_pointer<From>::type >::value,
+ "`agressive_ptr_cast` function must be used only for casting to or from void pointers."
+ );
+
+ BOOST_STATIC_ASSERT_MSG(
+ sizeof(v) == sizeof(typename boost::remove_reference<To>::type*),
+ "Pointer to function and pointer to object differ in size on your platform."
+ );
+
+ return static_cast<To>(
+ *reinterpret_cast<typename boost::remove_reference<To>::type*>(
+ *reinterpret_cast<boost::uintptr_t*>(
+ reinterpret_cast<unsigned char*>(
+ v
+ )
+ )
+ )
+ );
+}
+
+template <class To, class From>
+BOOST_FORCEINLINE typename boost::disable_if_c<!boost::is_member_pointer<To>::value || boost::is_member_pointer<From>::value, To>::type
+ aggressive_ptr_cast(From v) BOOST_NOEXCEPT
+{
+ BOOST_STATIC_ASSERT_MSG(
+ boost::is_pointer<From>::value,
+ "`agressive_ptr_cast` function must be used only for pointer casting."
+ );
+
+ BOOST_STATIC_ASSERT_MSG(
+ boost::is_void< typename boost::remove_pointer<From>::type >::value,
+ "`agressive_ptr_cast` function must be used only for casting to or from void pointers."
+ );
+
+ To res = 0;
+ std::memcpy(&res, &v, sizeof(To));
+ return res;
+}
+
+template <class To, class From>
+BOOST_FORCEINLINE typename boost::disable_if_c<boost::is_member_pointer<To>::value || !boost::is_member_pointer<From>::value, To>::type
+ aggressive_ptr_cast(From v) BOOST_NOEXCEPT
+{
+ BOOST_STATIC_ASSERT_MSG(
+ boost::is_pointer<To>::value,
+ "`agressive_ptr_cast` function must be used only for pointer casting."
+ );
+
+ BOOST_STATIC_ASSERT_MSG(
+ boost::is_void< typename boost::remove_pointer<To>::type >::value,
+ "`agressive_ptr_cast` function must be used only for casting to or from void pointers."
+ );
+
+ BOOST_STATIC_ASSERT_MSG(
+ !sizeof(From),
+ "Casting from member pointers to void pointer is not implemnted in `agressive_ptr_cast`."
+ );
+
+ return 0;
+}
+
+}}} // boost::dll::detail
+
+#endif // BOOST_DLL_DETAIL_AGGRESSIVE_PTR_CAST_HPP
+