1 // Copyright 2019 Hans Dembinski
2 //
3 // Distributed under the Boost Software License, Version 1.0.
4 // (See accompanying file LICENSE_1_0.txt
5 // or copy at http://www.boost.org/LICENSE_1_0.txt)
6
7 #ifndef BOOST_HISTOGRAM_DETAIL_ARRAY_WRAPPER_HPP
8 #define BOOST_HISTOGRAM_DETAIL_ARRAY_WRAPPER_HPP
9
10 #include <boost/core/nvp.hpp>
11 #include <boost/histogram/detail/span.hpp>
12 #include <boost/histogram/detail/static_if.hpp>
13 #include <boost/mp11/function.hpp>
14 #include <boost/mp11/utility.hpp>
15 #include <type_traits>
16
17 namespace boost {
18 namespace histogram {
19 namespace detail {
20
21 template <class T, class = decltype(&T::template save_array<int>)>
22 struct has_save_array_impl;
23
24 template <class T, class = decltype(&T::template load_array<int>)>
25 struct has_load_array_impl;
26
27 template <class T>
28 using has_array_optimization = mp11::mp_or<mp11::mp_valid<has_save_array_impl, T>,
29 mp11::mp_valid<has_load_array_impl, T>>;
30
31 template <class T>
32 struct array_wrapper {
33 using pointer = T*;
34
35 pointer ptr;
36 std::size_t size;
37
38 template <class Archive>
serializeboost::histogram::detail::array_wrapper39 void serialize(Archive& ar, unsigned /* version */) {
40 static_if_c<(has_array_optimization<Archive>::value &&
41 std::is_trivially_copyable<T>::value)>(
42 [this](auto& ar) {
43 // cannot use and therefore bypass save_array / load_array interface, because
44 // it requires exact type boost::serialization::array_wrapper<T>
45 static_if_c<Archive::is_loading::value>(
46 [this](auto& ar) { ar.load_binary(this->ptr, sizeof(T) * this->size); },
47 [this](auto& ar) { ar.save_binary(this->ptr, sizeof(T) * this->size); },
48 ar);
49 },
50 [this](auto& ar) {
51 for (auto&& x : boost::histogram::detail::make_span(this->ptr, this->size))
52 ar& make_nvp("item", x);
53 },
54 ar);
55 }
56 };
57
58 template <class T>
make_array_wrapper(T * t,std::size_t s)59 auto make_array_wrapper(T* t, std::size_t s) {
60 return array_wrapper<T>{t, s};
61 }
62
63 } // namespace detail
64 } // namespace histogram
65 } // namespace boost
66
67 #endif
68