1 | #pragma once |
2 | |
3 | #include <ciso646> // not |
4 | #include <cstddef> // size_t |
5 | #include <type_traits> // conditional, enable_if, false_type, integral_constant, is_constructible, is_integral, is_same, remove_cv, remove_reference, true_type |
6 | |
7 | namespace nlohmann |
8 | { |
9 | namespace detail |
10 | { |
11 | // alias templates to reduce boilerplate |
12 | template<bool B, typename T = void> |
13 | using enable_if_t = typename std::enable_if<B, T>::type; |
14 | |
15 | template<typename T> |
16 | using uncvref_t = typename std::remove_cv<typename std::remove_reference<T>::type>::type; |
17 | |
18 | // implementation of C++14 index_sequence and affiliates |
19 | // source: https://stackoverflow.com/a/32223343 |
20 | template<std::size_t... Ints> |
21 | struct index_sequence |
22 | { |
23 | using type = index_sequence; |
24 | using value_type = std::size_t; |
25 | static constexpr std::size_t size() noexcept |
26 | { |
27 | return sizeof...(Ints); |
28 | } |
29 | }; |
30 | |
31 | template<class Sequence1, class Sequence2> |
32 | struct merge_and_renumber; |
33 | |
34 | template<std::size_t... I1, std::size_t... I2> |
35 | struct merge_and_renumber<index_sequence<I1...>, index_sequence<I2...>> |
36 | : index_sequence < I1..., (sizeof...(I1) + I2)... > {}; |
37 | |
38 | template<std::size_t N> |
39 | struct make_index_sequence |
40 | : merge_and_renumber < typename make_index_sequence < N / 2 >::type, |
41 | typename make_index_sequence < N - N / 2 >::type > {}; |
42 | |
43 | template<> struct make_index_sequence<0> : index_sequence<> {}; |
44 | template<> struct make_index_sequence<1> : index_sequence<0> {}; |
45 | |
46 | template<typename... Ts> |
47 | using index_sequence_for = make_index_sequence<sizeof...(Ts)>; |
48 | |
49 | // dispatch utility (taken from ranges-v3) |
50 | template<unsigned N> struct priority_tag : priority_tag < N - 1 > {}; |
51 | template<> struct priority_tag<0> {}; |
52 | |
53 | // taken from ranges-v3 |
54 | template<typename T> |
55 | struct static_const |
56 | { |
57 | static constexpr T value{}; |
58 | }; |
59 | |
60 | template<typename T> |
61 | constexpr T static_const<T>::value; |
62 | } // namespace detail |
63 | } // namespace nlohmann |
64 | |