add nlohmann modenjson

5 files changed, 510 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..fa7478b
--- /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;
+}
+}
diff --git a/include/lib/modernjson/detail/meta/detected.hpp b/include/lib/modernjson/detail/meta/detected.hpp
new file mode 100644
index 0000000..78b25d5
--- /dev/null
+++ b/include/lib/modernjson/detail/meta/detected.hpp
@@ -0,0 +1,56 @@
+#pragma once
+
+#include <type_traits>
+
+#include <lib/modernjson/detail/meta/void_t.hpp>
+
+// http://en.cppreference.com/w/cpp/experimental/is_detected
+namespace nlohmann
+{
+namespace detail
+{
+struct nonesuch
+{
+    nonesuch() = delete;
+    ~nonesuch() = delete;
+    nonesuch(nonesuch const&) = delete;
+    void operator=(nonesuch const&) = delete;
+};
+
+template <class Default,
+          class AlwaysVoid,
+          template <class...> class Op,
+          class... Args>
+struct detector
+{
+    using value_t = std::false_type;
+    using type = Default;
+};
+
+template <class Default, template <class...> class Op, class... Args>
+struct detector<Default, void_t<Op<Args...>>, Op, Args...>
+{
+    using value_t = std::true_type;
+    using type = Op<Args...>;
+};
+
+template <template <class...> class Op, class... Args>
+using is_detected = typename detector<nonesuch, void, Op, Args...>::value_t;
+
+template <template <class...> class Op, class... Args>
+using detected_t = typename detector<nonesuch, void, Op, Args...>::type;
+
+template <class Default, template <class...> class Op, class... Args>
+using detected_or = detector<Default, void, Op, Args...>;
+
+template <class Default, template <class...> class Op, class... Args>
+using detected_or_t = typename detected_or<Default, Op, Args...>::type;
+
+template <class Expected, template <class...> class Op, class... Args>
+using is_detected_exact = std::is_same<Expected, detected_t<Op, Args...>>;
+
+template <class To, template <class...> class Op, class... Args>
+using is_detected_convertible =
+    std::is_convertible<detected_t<Op, Args...>, To>;
+}
+}
diff --git a/include/lib/modernjson/detail/meta/is_sax.hpp b/include/lib/modernjson/detail/meta/is_sax.hpp
new file mode 100644
index 0000000..63f9793
--- /dev/null
+++ b/include/lib/modernjson/detail/meta/is_sax.hpp
@@ -0,0 +1,141 @@
+#pragma once
+
+#include <cstdint> // size_t
+#include <utility> // declval
+
+#include <lib/modernjson/detail/meta/detected.hpp>
+#include <lib/modernjson/detail/meta/type_traits.hpp>
+
+namespace nlohmann
+{
+namespace detail
+{
+template <typename T>
+using null_function_t = decltype(std::declval<T&>().null());
+
+template <typename T>
+using boolean_function_t =
+    decltype(std::declval<T&>().boolean(std::declval<bool>()));
+
+template <typename T, typename Integer>
+using number_integer_function_t =
+    decltype(std::declval<T&>().number_integer(std::declval<Integer>()));
+
+template <typename T, typename Unsigned>
+using number_unsigned_function_t =
+    decltype(std::declval<T &>().number_unsigned(std::declval<Unsigned>()));
+
+template <typename T, typename Float, typename String>
+using number_float_function_t = decltype(std::declval<T &>().number_float(
+    std::declval<Float>(), std::declval<const String &>()));
+
+template <typename T, typename String>
+using string_function_t =
+    decltype(std::declval<T &>().string(std::declval<String &>()));
+
+template <typename T>
+using start_object_function_t =
+    decltype(std::declval<T &>().start_object(std::declval<std::size_t>()));
+
+template <typename T, typename String>
+using key_function_t =
+    decltype(std::declval<T &>().key(std::declval<String &>()));
+
+template <typename T>
+using end_object_function_t = decltype(std::declval<T &>().end_object());
+
+template <typename T>
+using start_array_function_t =
+    decltype(std::declval<T &>().start_array(std::declval<std::size_t>()));
+
+template <typename T>
+using end_array_function_t = decltype(std::declval<T &>().end_array());
+
+template <typename T, typename Exception>
+using parse_error_function_t = decltype(std::declval<T &>().parse_error(
+    std::declval<std::size_t>(), std::declval<const std::string &>(),
+    std::declval<const Exception &>()));
+
+template <typename SAX, typename BasicJsonType>
+struct is_sax
+{
+private:
+  static_assert(is_basic_json<BasicJsonType>::value,
+                "BasicJsonType must be of type basic_json<...>");
+
+  using number_integer_t = typename BasicJsonType::number_integer_t;
+  using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
+  using number_float_t = typename BasicJsonType::number_float_t;
+  using string_t = typename BasicJsonType::string_t;
+  using exception_t = typename BasicJsonType::exception;
+
+public:
+  static constexpr bool value =
+      is_detected_exact<bool, null_function_t, SAX>::value &&
+      is_detected_exact<bool, boolean_function_t, SAX>::value &&
+      is_detected_exact<bool, number_integer_function_t, SAX,
+                        number_integer_t>::value &&
+      is_detected_exact<bool, number_unsigned_function_t, SAX,
+                        number_unsigned_t>::value &&
+      is_detected_exact<bool, number_float_function_t, SAX, number_float_t,
+                        string_t>::value &&
+      is_detected_exact<bool, string_function_t, SAX, string_t>::value &&
+      is_detected_exact<bool, start_object_function_t, SAX>::value &&
+      is_detected_exact<bool, key_function_t, SAX, string_t>::value &&
+      is_detected_exact<bool, end_object_function_t, SAX>::value &&
+      is_detected_exact<bool, start_array_function_t, SAX>::value &&
+      is_detected_exact<bool, end_array_function_t, SAX>::value &&
+      is_detected_exact<bool, parse_error_function_t, SAX, exception_t>::value;
+};
+
+template <typename SAX, typename BasicJsonType>
+struct is_sax_static_asserts
+{
+private:
+  static_assert(is_basic_json<BasicJsonType>::value,
+                "BasicJsonType must be of type basic_json<...>");
+
+  using number_integer_t = typename BasicJsonType::number_integer_t;
+  using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
+  using number_float_t = typename BasicJsonType::number_float_t;
+  using string_t = typename BasicJsonType::string_t;
+  using exception_t = typename BasicJsonType::exception;
+
+public:
+  static_assert(is_detected_exact<bool, null_function_t, SAX>::value,
+                "Missing/invalid function: bool null()");
+  static_assert(is_detected_exact<bool, boolean_function_t, SAX>::value,
+                "Missing/invalid function: bool boolean(bool)");
+  static_assert(is_detected_exact<bool, boolean_function_t, SAX>::value,
+                "Missing/invalid function: bool boolean(bool)");
+  static_assert(
+      is_detected_exact<bool, number_integer_function_t, SAX,
+                        number_integer_t>::value,
+      "Missing/invalid function: bool number_integer(number_integer_t)");
+  static_assert(
+      is_detected_exact<bool, number_unsigned_function_t, SAX,
+                        number_unsigned_t>::value,
+      "Missing/invalid function: bool number_unsigned(number_unsigned_t)");
+  static_assert(is_detected_exact<bool, number_float_function_t, SAX,
+                                  number_float_t, string_t>::value,
+                "Missing/invalid function: bool number_float(number_float_t, const string_t&)");
+  static_assert(
+      is_detected_exact<bool, string_function_t, SAX, string_t>::value,
+      "Missing/invalid function: bool string(string_t&)");
+  static_assert(is_detected_exact<bool, start_object_function_t, SAX>::value,
+                "Missing/invalid function: bool start_object(std::size_t)");
+  static_assert(is_detected_exact<bool, key_function_t, SAX, string_t>::value,
+                "Missing/invalid function: bool key(string_t&)");
+  static_assert(is_detected_exact<bool, end_object_function_t, SAX>::value,
+                "Missing/invalid function: bool end_object()");
+  static_assert(is_detected_exact<bool, start_array_function_t, SAX>::value,
+                "Missing/invalid function: bool start_array(std::size_t)");
+  static_assert(is_detected_exact<bool, end_array_function_t, SAX>::value,
+                "Missing/invalid function: bool end_array()");
+  static_assert(
+      is_detected_exact<bool, parse_error_function_t, SAX, exception_t>::value,
+      "Missing/invalid function: bool parse_error(std::size_t, const "
+      "std::string&, const exception&)");
+};
+}
+}
diff --git a/include/lib/modernjson/detail/meta/type_traits.hpp b/include/lib/modernjson/detail/meta/type_traits.hpp
new file mode 100644
index 0000000..e5b6986
--- /dev/null
+++ b/include/lib/modernjson/detail/meta/type_traits.hpp
@@ -0,0 +1,237 @@
+#pragma once
+
+#include <ciso646> // not
+#include <limits> // numeric_limits
+#include <type_traits> // false_type, is_constructible, is_integral, is_same, true_type
+#include <utility> // declval
+
+#include <lib/modernjson/json_fwd.h>
+#include <lib/modernjson/detail/meta/cpp_future.hpp>
+#include <lib/modernjson/detail/meta/detected.hpp>
+#include <lib/modernjson/detail/macro_scope.hpp>
+
+namespace nlohmann
+{
+/*!
+@brief detail namespace with internal helper functions
+
+This namespace collects functions that should not be exposed,
+implementations of some @ref basic_json methods, and meta-programming helpers.
+
+@since version 2.1.0
+*/
+namespace detail
+{
+/////////////
+// helpers //
+/////////////
+
+template<typename> struct is_basic_json : std::false_type {};
+
+NLOHMANN_BASIC_JSON_TPL_DECLARATION
+struct is_basic_json<NLOHMANN_BASIC_JSON_TPL> : std::true_type {};
+
+//////////////////////////
+// aliases for detected //
+//////////////////////////
+
+template <typename T>
+using mapped_type_t = typename T::mapped_type;
+
+template <typename T>
+using key_type_t = typename T::key_type;
+
+template <typename T>
+using value_type_t = typename T::value_type;
+
+template <typename T>
+using difference_type_t = typename T::difference_type;
+
+template <typename T>
+using pointer_t = typename T::pointer;
+
+template <typename T>
+using reference_t = typename T::reference;
+
+template <typename T>
+using iterator_category_t = typename T::iterator_category;
+
+template <typename T>
+using iterator_t = typename T::iterator;
+
+template <typename T, typename... Args>
+using to_json_function = decltype(T::to_json(std::declval<Args>()...));
+
+template <typename T, typename... Args>
+using from_json_function = decltype(T::from_json(std::declval<Args>()...));
+
+///////////////////
+// is_ functions //
+///////////////////
+
+template <typename T, typename = void>
+struct is_iterator_traits : std::false_type {};
+
+template <typename T>
+struct is_iterator_traits<std::iterator_traits<T>>
+{
+  private:
+    using traits = std::iterator_traits<T>;
+
+  public:
+    static constexpr auto value =
+        is_detected<value_type_t, traits>::value &&
+        is_detected<difference_type_t, traits>::value &&
+        is_detected<pointer_t, traits>::value &&
+        is_detected<iterator_category_t, traits>::value &&
+        is_detected<reference_t, traits>::value;
+};
+
+// source: https://stackoverflow.com/a/37193089/4116453
+
+template <typename T, typename = void>
+struct is_complete_type : std::false_type {};
+
+template <typename T>
+struct is_complete_type<T, decltype(void(sizeof(T)))> : std::true_type {};
+
+template <typename BasicJsonType, typename CompatibleObjectType,
+          typename = void>
+struct is_compatible_object_type_impl : std::false_type {};
+
+template <typename BasicJsonType, typename CompatibleObjectType>
+struct is_compatible_object_type_impl <
+    BasicJsonType, CompatibleObjectType,
+    enable_if_t<is_detected<mapped_type_t, CompatibleObjectType>::value and
+    is_detected<key_type_t, CompatibleObjectType>::value >>
+{
+
+    using object_t = typename BasicJsonType::object_t;
+
+    // macOS's is_constructible does not play well with nonesuch...
+    static constexpr bool value =
+        std::is_constructible<typename object_t::key_type,
+        typename CompatibleObjectType::key_type>::value and
+        std::is_constructible<typename object_t::mapped_type,
+        typename CompatibleObjectType::mapped_type>::value;
+};
+
+template <typename BasicJsonType, typename CompatibleObjectType>
+struct is_compatible_object_type
+    : is_compatible_object_type_impl<BasicJsonType, CompatibleObjectType> {};
+
+template <typename BasicJsonType, typename CompatibleStringType,
+          typename = void>
+struct is_compatible_string_type_impl : std::false_type {};
+
+template <typename BasicJsonType, typename CompatibleStringType>
+struct is_compatible_string_type_impl <
+    BasicJsonType, CompatibleStringType,
+    enable_if_t<is_detected_exact<typename BasicJsonType::string_t::value_type,
+    value_type_t, CompatibleStringType>::value >>
+{
+    static constexpr auto value =
+        std::is_constructible<typename BasicJsonType::string_t, CompatibleStringType>::value;
+};
+
+template <typename BasicJsonType, typename CompatibleStringType>
+struct is_compatible_string_type
+    : is_compatible_string_type_impl<BasicJsonType, CompatibleStringType> {};
+
+template <typename BasicJsonType, typename CompatibleArrayType, typename = void>
+struct is_compatible_array_type_impl : std::false_type {};
+
+template <typename BasicJsonType, typename CompatibleArrayType>
+struct is_compatible_array_type_impl <
+    BasicJsonType, CompatibleArrayType,
+    enable_if_t<is_detected<value_type_t, CompatibleArrayType>::value and
+    is_detected<iterator_t, CompatibleArrayType>::value >>
+{
+    // This is needed because json_reverse_iterator has a ::iterator type...
+    // Therefore it is detected as a CompatibleArrayType.
+    // The real fix would be to have an Iterable concept.
+    static constexpr bool value = not is_iterator_traits<std::iterator_traits<CompatibleArrayType>>::value;
+};
+
+template <typename BasicJsonType, typename CompatibleArrayType>
+struct is_compatible_array_type
+    : is_compatible_array_type_impl<BasicJsonType, CompatibleArrayType> {};
+
+template <typename RealIntegerType, typename CompatibleNumberIntegerType,
+          typename = void>
+struct is_compatible_integer_type_impl : std::false_type {};
+
+template <typename RealIntegerType, typename CompatibleNumberIntegerType>
+struct is_compatible_integer_type_impl <
+    RealIntegerType, CompatibleNumberIntegerType,
+    enable_if_t<std::is_integral<RealIntegerType>::value and
+    std::is_integral<CompatibleNumberIntegerType>::value and
+    not std::is_same<bool, CompatibleNumberIntegerType>::value >>
+{
+    // is there an assert somewhere on overflows?
+    using RealLimits = std::numeric_limits<RealIntegerType>;
+    using CompatibleLimits = std::numeric_limits<CompatibleNumberIntegerType>;
+
+    static constexpr auto value =
+        std::is_constructible<RealIntegerType,
+        CompatibleNumberIntegerType>::value and
+        CompatibleLimits::is_integer and
+        RealLimits::is_signed == CompatibleLimits::is_signed;
+};
+
+template <typename RealIntegerType, typename CompatibleNumberIntegerType>
+struct is_compatible_integer_type
+    : is_compatible_integer_type_impl<RealIntegerType,
+      CompatibleNumberIntegerType> {};
+
+// trait checking if JSONSerializer<T>::from_json(json const&, udt&) exists
+template<typename BasicJsonType, typename T>
+struct has_from_json
+{
+    using serializer = typename BasicJsonType::template json_serializer<T, void>;
+
+    static constexpr bool value =
+        is_detected_exact<void, from_json_function, serializer,
+        const BasicJsonType&, T&>::value;
+};
+
+// This trait checks if JSONSerializer<T>::from_json(json const&) exists
+// this overload is used for non-default-constructible user-defined-types
+template<typename BasicJsonType, typename T>
+struct has_non_default_from_json
+{
+    using serializer = typename BasicJsonType::template json_serializer<T, void>;
+
+    static constexpr bool value =
+        is_detected_exact<T, from_json_function, serializer,
+        const BasicJsonType&>::value;
+};
+
+// This trait checks if BasicJsonType::json_serializer<T>::to_json exists
+template<typename BasicJsonType, typename T>
+struct has_to_json
+{
+    using serializer = typename BasicJsonType::template json_serializer<T, void>;
+
+    static constexpr bool value =
+        is_detected_exact<void, to_json_function, serializer, BasicJsonType&,
+        T>::value;
+};
+
+template <typename BasicJsonType, typename CompatibleType, typename = void>
+struct is_compatible_type_impl: std::false_type {};
+
+template <typename BasicJsonType, typename CompatibleType>
+struct is_compatible_type_impl <
+    BasicJsonType, CompatibleType,
+    enable_if_t<is_complete_type<CompatibleType>::value >>
+{
+    static constexpr bool value =
+        has_to_json<BasicJsonType, CompatibleType>::value;
+};
+
+template <typename BasicJsonType, typename CompatibleType>
+struct is_compatible_type
+    : is_compatible_type_impl<BasicJsonType, CompatibleType> {};
+}
+}
diff --git a/include/lib/modernjson/detail/meta/void_t.hpp b/include/lib/modernjson/detail/meta/void_t.hpp
new file mode 100644
index 0000000..2528ea8
--- /dev/null
+++ b/include/lib/modernjson/detail/meta/void_t.hpp
@@ -0,0 +1,13 @@
+#pragma once
+
+namespace nlohmann
+{
+namespace detail
+{
+template <typename ...Ts> struct make_void
+{
+    using type = void;
+};
+template <typename ...Ts> using void_t = typename make_void<Ts...>::type;
+}
+}