Vc/traits/has_no_allocated_data.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_TRAITS_HAS_NO_ALLOCATED_DATA_H_
0029 #define VC_TRAITS_HAS_NO_ALLOCATED_DATA_H_
0030
0031 #include <array>
0032
0033 namespace Vc_VERSIONED_NAMESPACE
0034 {
0035 namespace Traits
0036 {
0037
0038 /**
0039  * Implements the has_no_allocated_data trait.
0040  *
0041  * Specialize this type for your container class if you need to make it usable with SIMD
0042  * gathers/scatters. Example:
0043  * \code
0044  * namespace Vc
0045  * {
0046  * namespace Traits
0047  * {
0048  * template<typename T> struct has_no_allocated_data_impl<MyContainer<T>> : public std::true_type {};
0049  * }
0050  * }
0051  * \endcode
0052  *
0053  * \see has_no_allocated_data
0054  */
0055 template<typename T> struct has_no_allocated_data_impl : public std::false_type {};
0056
0057 /**
0058  * Type trait that tells whether a container stores its data inside the object or inside allocated
0059  * memory outside of the object.
0060  *
0061  * Per default the trait assumes any type to store its data outside, on the heap. The only types
0062  * where it knows that the storage is inside the object are std::array, Vc::array, and T[] (builtin
0063  * arrays).
0064  *
0065  * The trait forwards the actual decision to has_no_allocated_data_impl, but removes const/volatile
0066  * and references from the type \p T to make the number of required specializations of
0067  * has_no_allocated_data_impl minimal.
0068  */
0069 template <typename T>
0070 struct has_no_allocated_data
0071     : public has_no_allocated_data_impl<
0072           typename std::remove_cv<typename std::remove_reference<T>::type>::type>
0073 {
0074 };
0075
0076 // spezializations:
0077 template<typename T, std::size_t N> struct has_no_allocated_data_impl<std::array<T, N>> : public std::true_type {};
0078 template<typename T, std::size_t N> struct has_no_allocated_data_impl<T[N]> : public std::true_type {};
0079 template<typename T> struct has_no_allocated_data_impl<T[]> : public std::true_type {};
0080 }  // namespace Traits
0081 }  // namespace Vc
0082
0083 #endif // VC_TRAITS_HAS_NO_ALLOCATED_DATA_H_