Vc/common/simd_cast.h

0001 /*  This file is part of the Vc library. {{{
0002 Copyright © 2014-2015 Matthias Kretz <kretz@kde.org>
0003
0004 Redistribution and use in source and binary forms, with or without
0005 modification, are permitted provided that the following conditions are met:
0006     * Redistributions of source code must retain the above copyright
0007       notice, this list of conditions and the following disclaimer.
0008     * Redistributions in binary form must reproduce the above copyright
0009       notice, this list of conditions and the following disclaimer in the
0010       documentation and/or other materials provided with the distribution.
0011     * Neither the names of contributing organizations nor the
0012       names of its contributors may be used to endorse or promote products
0013       derived from this software without specific prior written permission.
0014
0015 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
0016 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
0017 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
0018 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
0019 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
0020 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
0021 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
0022 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
0023 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
0024 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
0025
0026 }}}*/
0027
0028 #ifndef VC_COMMON_SIMD_CAST_H_
0029 #define VC_COMMON_SIMD_CAST_H_
0030
0031 #include <type_traits>
0032 #include "macros.h"
0033
0034 // declare a bogus simd_cast function template in the global namespace to enable ADL for
0035 // simd_cast<T>
0036 template <class> void simd_cast();
0037
0038 namespace Vc_VERSIONED_NAMESPACE
0039 {
0040 /**
0041  * Casts the argument \p x from type \p From to type \p To.
0042  *
0043  * This function implements the trivial case where \p To and \p From are the same type.
0044  *
0045  * \param x The object of type \p From to be converted to type \p To.
0046  * \returns An object of type \p To with all vector components converted according to
0047  *          standard conversion behavior as mandated by the C++ standard for the
0048  *          underlying arithmetic types.
0049  */
0050 template <typename To, typename From>
0051 Vc_INTRINSIC Vc_CONST To
0052 simd_cast(From &&x, enable_if<std::is_same<To, Traits::decay<From>>::value> = nullarg)
0053 {
0054     return std::forward<From>(x);
0055 }
0056
0057 /**
0058  * A cast from nothing results in default-initialization of \p To.
0059  *
0060  * This function can be useful in generic code where a parameter pack expands to nothing.
0061  *
0062  * \returns A zero-initialized object of type \p To.
0063  */
0064 template <typename To> Vc_INTRINSIC Vc_CONST To simd_cast() { return To(); }
0065
0066 }  // namespace Vc
0067
0068 #endif // VC_COMMON_SIMD_CAST_H_