| /* |
| * Copyright (C) 2019 Apple Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
| * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #ifndef StdLibExtras_h |
| #define StdLibExtras_h |
| |
| #include "BCompiler.h" |
| #include <memory> |
| #include <type_traits> |
| |
| namespace bmalloc { |
| |
| template<typename ToType, typename FromType> |
| inline ToType bitwise_cast(FromType from) |
| { |
| static_assert(sizeof(FromType) == sizeof(ToType), "bitwise_cast size of FromType and ToType must be equal!"); |
| #if BCOMPILER_HAS_CLANG_FEATURE(is_trivially_copyable) |
| // Not all recent STL implementations support the std::is_trivially_copyable type trait. Work around this by only checking on toolchains which have the equivalent compiler intrinsic. |
| static_assert(__is_trivially_copyable(ToType), "bitwise_cast of non-trivially-copyable type!"); |
| static_assert(__is_trivially_copyable(FromType), "bitwise_cast of non-trivially-copyable type!"); |
| #endif |
| typename std::remove_const<ToType>::type to { }; |
| memcpy(static_cast<void*>(&to), static_cast<void*>(&from), sizeof(to)); |
| return to; |
| } |
| |
| } // namespace bmalloc |
| |
| #endif // StdLibExtras_h |