Remove static asserts

include/nlohmann/adl_serializer.hpp

@@ -20,8 +20,10 @@ struct adl_serializer
  @param[in,out] val value to write to
  */
  template<typename BasicJsonType, typename ValueType>
- static void from_json(BasicJsonType&& j, ValueType& val) noexcept(
- noexcept(::nlohmann::from_json(std::forward<BasicJsonType>(j), val)))
+ static auto from_json(BasicJsonType&& j, ValueType& val) noexcept(
+ noexcept(::nlohmann::from_json(std::forward<BasicJsonType>(j), val))) -> decltype(
+ ::nlohmann::from_json(std::forward<BasicJsonType>(j), val), void()
+ )
  {
  ::nlohmann::from_json(std::forward<BasicJsonType>(j), val);
  }
@@ -35,9 +37,11 @@ struct adl_serializer
  @param[in,out] j JSON value to write to
  @param[in] val value to read from
  */
- template<typename BasicJsonType, typename ValueType>
- static void to_json(BasicJsonType& j, ValueType&& val) noexcept(
+ template <typename BasicJsonType, typename ValueType>
+ static auto to_json(BasicJsonType& j, ValueType&& val) noexcept(
  noexcept(::nlohmann::to_json(j, std::forward<ValueType>(val))))
+ -> decltype(::nlohmann::to_json(j, std::forward<ValueType>(val)),
+ void())
  {
  ::nlohmann::to_json(j, std::forward<ValueType>(val));
  }

include/nlohmann/detail/conversions/from_json.hpp

@@ -127,16 +127,6 @@ void from_json(const BasicJsonType& j, EnumType& e)
  e = static_cast<EnumType>(val);
 }
 
-template<typename BasicJsonType>
-void from_json(const BasicJsonType& j, typename BasicJsonType::array_t& arr)
-{
- if (JSON_UNLIKELY(not j.is_array()))
- {
- JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name())));
- }
- arr = *j.template get_ptr<const typename BasicJsonType::array_t*>();
-}
-
 // forward_list doesn't have an insert method
 template<typename BasicJsonType, typename T, typename Allocator,
  enable_if_t<std::is_convertible<BasicJsonType, T>::value, int> = 0>
@@ -166,24 +156,28 @@ void from_json(const BasicJsonType& j, std::valarray<T>& l)
  std::copy(j.m_value.array->begin(), j.m_value.array->end(), std::begin(l));
 }
 
-template<typename BasicJsonType, typename CompatibleArrayType>
-void from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, priority_tag<0> /*unused*/)
+template<typename BasicJsonType>
+void from_json_array_impl(const BasicJsonType& j, typename BasicJsonType::array_t& arr, priority_tag<3> /*unused*/)
 {
- using std::end;
+ arr = *j.template get_ptr<const typename BasicJsonType::array_t*>();
+}
 
- std::transform(j.begin(), j.end(),
- std::inserter(arr, end(arr)), [](const BasicJsonType & i)
+template <typename BasicJsonType, typename T, std::size_t N>
+auto from_json_array_impl(const BasicJsonType& j, std::array<T, N>& arr,
+ priority_tag<2> /*unused*/)
+-> decltype(j.template get<T>(), void())
+{
+ for (std::size_t i = 0; i < N; ++i)
  {
- // get<BasicJsonType>() returns *this, this won't call a from_json
- // method when value_type is BasicJsonType
- return i.template get<typename CompatibleArrayType::value_type>();
- });
+ arr[i] = j.at(i).template get<T>();
+ }
 }
 
 template<typename BasicJsonType, typename CompatibleArrayType>
 auto from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, priority_tag<1> /*unused*/)
 -> decltype(
  arr.reserve(std::declval<typename CompatibleArrayType::size_type>()),
+ j.template get<typename CompatibleArrayType::value_type>(),
  void())
 {
  using std::end;
@@ -198,33 +192,42 @@ auto from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, prio
  });
 }
 
-template<typename BasicJsonType, typename T, std::size_t N>
-void from_json_array_impl(const BasicJsonType& j, std::array<T, N>& arr, priority_tag<2> /*unused*/)
+template <typename BasicJsonType, typename CompatibleArrayType>
+void from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr,
+ priority_tag<0> /*unused*/)
 {
- for (std::size_t i = 0; i < N; ++i)
+ using std::end;
+
+ std::transform(
+ j.begin(), j.end(), std::inserter(arr, end(arr)),
+ [](const BasicJsonType & i)
  {
- arr[i] = j.at(i).template get<T>();
- }
+ // get<BasicJsonType>() returns *this, this won't call a from_json
+ // method when value_type is BasicJsonType
+ return i.template get<typename CompatibleArrayType::value_type>();
+ });
 }
 
-template <
- typename BasicJsonType, typename CompatibleArrayType,
- enable_if_t <
- is_compatible_array_type<BasicJsonType, CompatibleArrayType>::value and
- not std::is_same<typename BasicJsonType::array_t,
- CompatibleArrayType>::value and
- std::is_constructible <
- BasicJsonType, typename CompatibleArrayType::value_type >::value,
- int > = 0 >
-void from_json(const BasicJsonType& j, CompatibleArrayType& arr)
+template <typename BasicJsonType, typename CompatibleArrayType,
+ enable_if_t <
+ is_compatible_array_type<BasicJsonType, CompatibleArrayType>::value and
+ not is_compatible_object_type<BasicJsonType, CompatibleArrayType>::value and
+ not is_compatible_string_type<BasicJsonType, CompatibleArrayType>::value and
+ not is_basic_json<CompatibleArrayType>::value,
+ int > = 0 >
+
+auto from_json(const BasicJsonType& j, CompatibleArrayType& arr)
+-> decltype(from_json_array_impl(j, arr, priority_tag<3> {}),
+ j.template get<typename CompatibleArrayType::value_type>(),
+ void())
 {
  if (JSON_UNLIKELY(not j.is_array()))
  {
  JSON_THROW(type_error::create(302, "type must be array, but is " +
  std::string(j.type_name())));
  }
 
- from_json_array_impl(j, arr, priority_tag<2> {});
+ from_json_array_impl(j, arr, priority_tag<3> {});
 }
 
 template<typename BasicJsonType, typename CompatibleObjectType,
@@ -347,35 +350,13 @@ void from_json(const BasicJsonType& j, std::unordered_map<Key, Value, Hash, KeyE
 
 struct from_json_fn
 {
- private:
  template<typename BasicJsonType, typename T>
- auto call(const BasicJsonType& j, T& val, priority_tag<1> /*unused*/) const
+ auto operator()(const BasicJsonType& j, T& val) const
  noexcept(noexcept(from_json(j, val)))
  -> decltype(from_json(j, val), void())
  {
  return from_json(j, val);
  }
-
- template<typename BasicJsonType, typename T>
- void call(const BasicJsonType& /*unused*/, T& /*unused*/, priority_tag<0> /*unused*/) const noexcept
- {
- static_assert(sizeof(BasicJsonType) == 0,
- "could not find from_json() method in T's namespace");
-#ifdef _MSC_VER
- // MSVC does not show a stacktrace for the above assert
- using decayed = uncvref_t<T>;
- static_assert(sizeof(typename decayed::force_msvc_stacktrace) == 0,
- "forcing MSVC stacktrace to show which T we're talking about.");
-#endif
- }
-
- public:
- template<typename BasicJsonType, typename T>
- void operator()(const BasicJsonType& j, T& val) const
- noexcept(noexcept(std::declval<from_json_fn>().call(j, val, priority_tag<1> {})))
- {
- return call(j, val, priority_tag<1> {});
- }
 };
 }
 

include/nlohmann/detail/conversions/to_json.hpp

@@ -248,10 +248,14 @@ void to_json(BasicJsonType& j, const std::vector<bool>& e)
  external_constructor<value_t::array>::construct(j, e);
 }
 
-template<typename BasicJsonType, typename CompatibleArrayType,
- enable_if_t<is_compatible_array_type<BasicJsonType, CompatibleArrayType>::value or
- std::is_same<typename BasicJsonType::array_t, CompatibleArrayType>::value,
- int> = 0>
+template <typename BasicJsonType, typename CompatibleArrayType,
+ enable_if_t<is_compatible_array_type<BasicJsonType,
+ CompatibleArrayType>::value and
+ not is_compatible_object_type<
+ BasicJsonType, CompatibleArrayType>::value and
+ not is_compatible_string_type<BasicJsonType, CompatibleArrayType>::value and
+ not is_basic_json<CompatibleArrayType>::value,
+ int> = 0>
 void to_json(BasicJsonType& j, const CompatibleArrayType& arr)
 {
  external_constructor<value_t::array>::construct(j, arr);
@@ -271,7 +275,7 @@ void to_json(BasicJsonType& j, typename BasicJsonType::array_t&& arr)
 }
 
 template<typename BasicJsonType, typename CompatibleObjectType,
- enable_if_t<is_compatible_object_type<BasicJsonType, CompatibleObjectType>::value, int> = 0>
+ enable_if_t<is_compatible_object_type<BasicJsonType, CompatibleObjectType>::value and not is_basic_json<CompatibleObjectType>::value, int> = 0>
 void to_json(BasicJsonType& j, const CompatibleObjectType& obj)
 {
  external_constructor<value_t::object>::construct(j, obj);
@@ -283,9 +287,12 @@ void to_json(BasicJsonType& j, typename BasicJsonType::object_t&& obj)
  external_constructor<value_t::object>::construct(j, std::move(obj));
 }
 
-template<typename BasicJsonType, typename T, std::size_t N,
- enable_if_t<not std::is_constructible<typename BasicJsonType::string_t, T (&)[N]>::value, int> = 0>
-void to_json(BasicJsonType& j, T (&arr)[N])
+template <
+ typename BasicJsonType, typename T, std::size_t N,
+ enable_if_t<not std::is_constructible<typename BasicJsonType::string_t,
+ const T (&)[N]>::value,
+ int> = 0 >
+void to_json(BasicJsonType& j, const T (&arr)[N])
 {
  external_constructor<value_t::array>::construct(j, arr);
 }
@@ -318,35 +325,12 @@ void to_json(BasicJsonType& j, const std::tuple<Args...>& t)
 
 struct to_json_fn
 {
- private:
  template<typename BasicJsonType, typename T>
- auto call(BasicJsonType& j, T&& val, priority_tag<1> /*unused*/) const noexcept(noexcept(to_json(j, std::forward<T>(val))))
+ auto operator()(BasicJsonType& j, T&& val) const noexcept(noexcept(to_json(j, std::forward<T>(val))))
  -> decltype(to_json(j, std::forward<T>(val)), void())
  {
  return to_json(j, std::forward<T>(val));
  }
-
- template<typename BasicJsonType, typename T>
- void call(BasicJsonType& /*unused*/, T&& /*unused*/, priority_tag<0> /*unused*/) const noexcept
- {
- static_assert(sizeof(BasicJsonType) == 0,
- "could not find to_json() method in T's namespace");
-
-#ifdef _MSC_VER
- // MSVC does not show a stacktrace for the above assert
- using decayed = uncvref_t<T>;
- static_assert(sizeof(typename decayed::force_msvc_stacktrace) == 0,
- "forcing MSVC stacktrace to show which T we're talking about.");
-#endif
- }
-
- public:
- template<typename BasicJsonType, typename T>
- void operator()(BasicJsonType& j, T&& val) const
- noexcept(noexcept(std::declval<to_json_fn>().call(j, std::forward<T>(val), priority_tag<1> {})))
- {
- return call(j, std::forward<T>(val), priority_tag<1> {});
- }
 };
 }
 

include/nlohmann/detail/macro_scope.hpp

@@ -102,22 +102,3 @@
  basic_json<ObjectType, ArrayType, StringType, BooleanType, \
  NumberIntegerType, NumberUnsignedType, NumberFloatType, \
  AllocatorType, JSONSerializer>
-
-/*!
-@brief Helper to determine whether there's a key_type for T.
-
-This helper is used to tell associative containers apart from other containers
-such as sequence containers. For instance, `std::map` passes the test as it
-contains a `mapped_type`, whereas `std::vector` fails the test.
-
-@sa http://stackoverflow.com/a/7728728/266378
-@since version 1.0.0, overworked in version 2.0.6
-*/
-#define NLOHMANN_JSON_HAS_HELPER(type) \
- template<typename T> struct has_##type { \
- template<typename U, typename = typename U::type> \
- static int detect(U &&); \
- static void detect(...); \
- static constexpr bool value = \
- std::is_integral<decltype(detect(std::declval<T>()))>::value; \
- }

include/nlohmann/detail/macro_unscope.hpp

@@ -20,4 +20,3 @@
 #undef JSON_HAS_CPP_17
 #undef NLOHMANN_BASIC_JSON_TPL_DECLARATION
 #undef NLOHMANN_BASIC_JSON_TPL
-#undef NLOHMANN_JSON_HAS_HELPER

include/nlohmann/detail/meta/cpp_future.hpp

@@ -46,26 +46,6 @@ template<> struct make_index_sequence<1> : index_sequence<0> {};
 template<typename... Ts>
 using index_sequence_for = make_index_sequence<sizeof...(Ts)>;
 
-/*
-Implementation of two C++17 constructs: conjunction, negation. This is needed
-to avoid evaluating all the traits in a condition
-
-For example: not std::is_same<void, T>::value and has_value_type<T>::value
-will not compile when T = void (on MSVC at least). Whereas
-conjunction<negation<std::is_same<void, T>>, has_value_type<T>>::value will
-stop evaluating if negation<...>::value == false
-
-Please note that those constructs must be used with caution, since symbols can
-become very long quickly (which can slow down compilation and cause MSVC
-internal compiler errors). Only use it when you have to (see example ahead).
-*/
-template<class...> struct conjunction : std::true_type {};
-template<class B1> struct conjunction<B1> : B1 {};
-template<class B1, class... Bn>
-struct conjunction<B1, Bn...> : std::conditional<bool(B1::value), conjunction<Bn...>, B1>::type {};
-
-template<class B> struct negation : std::integral_constant<bool, not B::value> {};
-
 // dispatch utility (taken from ranges-v3)
 template<unsigned N> struct priority_tag : priority_tag < N - 1 > {};
 template<> struct priority_tag<0> {};