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Diffstat (limited to 'include/lib/modernjson/detail/meta/cpp_future.hpp')
-rw-r--r-- | include/lib/modernjson/detail/meta/cpp_future.hpp | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/include/lib/modernjson/detail/meta/cpp_future.hpp b/include/lib/modernjson/detail/meta/cpp_future.hpp new file mode 100644 index 0000000..948cd4f --- /dev/null +++ b/include/lib/modernjson/detail/meta/cpp_future.hpp @@ -0,0 +1,63 @@ +#pragma once + +#include <ciso646> // not +#include <cstddef> // size_t +#include <type_traits> // conditional, enable_if, false_type, integral_constant, is_constructible, is_integral, is_same, remove_cv, remove_reference, true_type + +namespace nlohmann +{ +namespace detail +{ +// alias templates to reduce boilerplate +template<bool B, typename T = void> +using enable_if_t = typename std::enable_if<B, T>::type; + +template<typename T> +using uncvref_t = typename std::remove_cv<typename std::remove_reference<T>::type>::type; + +// implementation of C++14 index_sequence and affiliates +// source: https://stackoverflow.com/a/32223343 +template<std::size_t... Ints> +struct index_sequence +{ + using type = index_sequence; + using value_type = std::size_t; + static constexpr std::size_t size() noexcept + { + return sizeof...(Ints); + } +}; + +template<class Sequence1, class Sequence2> +struct merge_and_renumber; + +template<std::size_t... I1, std::size_t... I2> +struct merge_and_renumber<index_sequence<I1...>, index_sequence<I2...>> + : index_sequence < I1..., (sizeof...(I1) + I2)... > {}; + +template<std::size_t N> +struct make_index_sequence + : merge_and_renumber < typename make_index_sequence < N / 2 >::type, + typename make_index_sequence < N - N / 2 >::type > {}; + +template<> struct make_index_sequence<0> : index_sequence<> {}; +template<> struct make_index_sequence<1> : index_sequence<0> {}; + +template<typename... Ts> +using index_sequence_for = make_index_sequence<sizeof...(Ts)>; + +// dispatch utility (taken from ranges-v3) +template<unsigned N> struct priority_tag : priority_tag < N - 1 > {}; +template<> struct priority_tag<0> {}; + +// taken from ranges-v3 +template<typename T> +struct static_const +{ + static constexpr T value{}; +}; + +template<typename T> +constexpr T static_const<T>::value; +} // namespace detail +} // namespace nlohmann |