nlohmannjson/include/nlohmann/detail/meta/is_sax.hpp

#pragma once

#include <cstdint> // size_t
#include <utility> // declval

#include <nlohmann/detail/meta/detected.hpp>
#include <nlohmann/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&)");
};
}
}