From f364f5ac5a4aa17c2af5a2d94d7b7f478e58ac43 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Th=C3=A9o=20DELRIEU?= <delrieutheo@gmail.com>
Date: Mon, 14 Aug 2017 15:06:35 +0200
Subject: [PATCH] add detail/meta.hpp
---
Makefile | 4 +-
src/detail/meta.hpp | 226 ++++++++++++++++++++++++++++++++++++++++++++
src/json.hpp | 212 +----------------------------------------
3 files changed, 230 insertions(+), 212 deletions(-)
create mode 100644 src/detail/meta.hpp
diff --git a/Makefile b/Makefile
index 3f1e3337..6600e00b 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,9 @@ SRCDIR = src
SRCS = ${SRCDIR}/json.hpp \
${SRCDIR}/json_fwd.hpp \
${SRCDIR}/detail/macro_scope.hpp \
- ${SRCDIR}/detail/macro_unscope.hpp
+ ${SRCDIR}/detail/macro_unscope.hpp \
+ ${SRCDIR}/detail/meta.hpp
+
# main target
all:
diff --git a/src/detail/meta.hpp b/src/detail/meta.hpp
new file mode 100644
index 00000000..9a3a97fa
--- /dev/null
+++ b/src/detail/meta.hpp
@@ -0,0 +1,226 @@
+#ifndef NLOHMANN_JSON_DETAIL_META_HPP
+#define NLOHMANN_JSON_DETAIL_META_HPP
+
+#include <cstdint>
+#include <limits>
+#include <type_traits> // add_pointer, conditional, decay, enable_if, false_type, integral_constant, is_arithmetic, is_base_of, is_const, is_constructible, is_convertible, is_default_constructible, is_enum, is_floating_point, is_integral, is_nothrow_move_assignable, is_nothrow_move_constructible, is_pointer, is_reference, is_same, is_scalar, is_signed, remove_const, remove_cv, remove_pointer, remove_reference, true_type, underlying_type
+#include <utility>
+
+#include "json_fwd.hpp"
+#include "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 {};
+
+// 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)>;
+
+/*
+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> {};
+
+////////////////////////
+// has_/is_ functions //
+////////////////////////
+
+NLOHMANN_JSON_HAS_HELPER(mapped_type);
+NLOHMANN_JSON_HAS_HELPER(key_type);
+NLOHMANN_JSON_HAS_HELPER(value_type);
+NLOHMANN_JSON_HAS_HELPER(iterator);
+
+template<bool B, class RealType, class CompatibleObjectType>
+struct is_compatible_object_type_impl : std::false_type {};
+
+template<class RealType, class CompatibleObjectType>
+struct is_compatible_object_type_impl<true, RealType, CompatibleObjectType>
+{
+ static constexpr auto value =
+ std::is_constructible<typename RealType::key_type, typename CompatibleObjectType::key_type>::value and
+ std::is_constructible<typename RealType::mapped_type, typename CompatibleObjectType::mapped_type>::value;
+};
+
+template<class BasicJsonType, class CompatibleObjectType>
+struct is_compatible_object_type
+{
+ static auto constexpr value = is_compatible_object_type_impl <
+ conjunction<negation<std::is_same<void, CompatibleObjectType>>,
+ has_mapped_type<CompatibleObjectType>,
+ has_key_type<CompatibleObjectType>>::value,
+ typename BasicJsonType::object_t, CompatibleObjectType >::value;
+};
+
+template<typename BasicJsonType, typename T>
+struct is_basic_json_nested_type
+{
+ static auto constexpr value = std::is_same<T, typename BasicJsonType::iterator>::value or
+ std::is_same<T, typename BasicJsonType::const_iterator>::value or
+ std::is_same<T, typename BasicJsonType::reverse_iterator>::value or
+ std::is_same<T, typename BasicJsonType::const_reverse_iterator>::value;
+};
+
+template<class BasicJsonType, class CompatibleArrayType>
+struct is_compatible_array_type
+{
+ static auto constexpr value =
+ conjunction<negation<std::is_same<void, CompatibleArrayType>>,
+ negation<is_compatible_object_type<
+ BasicJsonType, CompatibleArrayType>>,
+ negation<std::is_constructible<typename BasicJsonType::string_t,
+ CompatibleArrayType>>,
+ negation<is_basic_json_nested_type<BasicJsonType, CompatibleArrayType>>,
+ has_value_type<CompatibleArrayType>,
+ has_iterator<CompatibleArrayType>>::value;
+};
+
+template<bool, typename, typename>
+struct is_compatible_integer_type_impl : std::false_type {};
+
+template<typename RealIntegerType, typename CompatibleNumberIntegerType>
+struct is_compatible_integer_type_impl<true, RealIntegerType, CompatibleNumberIntegerType>
+{
+ // 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
+{
+ static constexpr auto value =
+ is_compatible_integer_type_impl <
+ std::is_integral<CompatibleNumberIntegerType>::value and
+ not std::is_same<bool, CompatibleNumberIntegerType>::value,
+ RealIntegerType, CompatibleNumberIntegerType > ::value;
+};
+
+
+// trait checking if JSONSerializer<T>::from_json(json const&, udt&) exists
+template<typename BasicJsonType, typename T>
+struct has_from_json
+{
+ private:
+ // also check the return type of from_json
+ template<typename U, typename = enable_if_t<std::is_same<void, decltype(uncvref_t<U>::from_json(
+ std::declval<BasicJsonType>(), std::declval<T&>()))>::value>>
+ static int detect(U&&);
+ static void detect(...);
+
+ public:
+ static constexpr bool value = std::is_integral<decltype(
+ detect(std::declval<typename BasicJsonType::template json_serializer<T, void>>()))>::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
+{
+ private:
+ template <
+ typename U,
+ typename = enable_if_t<std::is_same<
+ T, decltype(uncvref_t<U>::from_json(std::declval<BasicJsonType>()))>::value >>
+ static int detect(U&&);
+ static void detect(...);
+
+ public:
+ static constexpr bool value = std::is_integral<decltype(detect(
+ std::declval<typename BasicJsonType::template json_serializer<T, void>>()))>::value;
+};
+
+// This trait checks if BasicJsonType::json_serializer<T>::to_json exists
+template<typename BasicJsonType, typename T>
+struct has_to_json
+{
+ private:
+ template<typename U, typename = decltype(uncvref_t<U>::to_json(
+ std::declval<BasicJsonType&>(), std::declval<T>()))>
+ static int detect(U&&);
+ static void detect(...);
+
+ public:
+ static constexpr bool value = std::is_integral<decltype(detect(
+ std::declval<typename BasicJsonType::template json_serializer<T, void>>()))>::value;
+};
+}
+}
+
+#endif
diff --git a/src/json.hpp b/src/json.hpp
index 3555400a..7b37521a 100644
--- a/src/json.hpp
+++ b/src/json.hpp
@@ -48,12 +48,12 @@ SOFTWARE.
#include <locale> // locale
#include <numeric> // accumulate
#include <sstream> // stringstream
-#include <type_traits> // add_pointer, conditional, decay, enable_if, false_type, integral_constant, is_arithmetic, is_base_of, is_const, is_constructible, is_convertible, is_default_constructible, is_enum, is_floating_point, is_integral, is_nothrow_move_assignable, is_nothrow_move_constructible, is_pointer, is_reference, is_same, is_scalar, is_signed, remove_const, remove_cv, remove_pointer, remove_reference, true_type, underlying_type
#include <utility> // declval, forward, make_pair, move, pair, swap
#include <valarray> // valarray
#include "json_fwd.hpp"
#include "detail/macro_scope.hpp"
+#include "detail/meta.hpp"
/*!
@brief namespace for Niels Lohmann
@@ -62,14 +62,6 @@ SOFTWARE.
*/
namespace nlohmann
{
-/*!
-@brief unnamed namespace with internal helper functions
-
-This namespace collects some functions that could not be defined inside the
-@ref basic_json class.
-
-@since version 2.1.0
-*/
namespace detail
{
////////////////
@@ -455,79 +447,6 @@ inline bool operator<(const value_t lhs, const value_t rhs) noexcept
return l_index < order.size() and r_index < order.size() and order[l_index] < order[r_index];
}
-
-/////////////
-// 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 {};
-
-// 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)>;
-
-/*
-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> {};
-
-
//////////////////
// constructors //
//////////////////
@@ -690,135 +609,6 @@ struct external_constructor<value_t::object>
}
};
-
-////////////////////////
-// has_/is_ functions //
-////////////////////////
-
-NLOHMANN_JSON_HAS_HELPER(mapped_type);
-NLOHMANN_JSON_HAS_HELPER(key_type);
-NLOHMANN_JSON_HAS_HELPER(value_type);
-NLOHMANN_JSON_HAS_HELPER(iterator);
-
-template<bool B, class RealType, class CompatibleObjectType>
-struct is_compatible_object_type_impl : std::false_type {};
-
-template<class RealType, class CompatibleObjectType>
-struct is_compatible_object_type_impl<true, RealType, CompatibleObjectType>
-{
- static constexpr auto value =
- std::is_constructible<typename RealType::key_type, typename CompatibleObjectType::key_type>::value and
- std::is_constructible<typename RealType::mapped_type, typename CompatibleObjectType::mapped_type>::value;
-};
-
-template<class BasicJsonType, class CompatibleObjectType>
-struct is_compatible_object_type
-{
- static auto constexpr value = is_compatible_object_type_impl <
- conjunction<negation<std::is_same<void, CompatibleObjectType>>,
- has_mapped_type<CompatibleObjectType>,
- has_key_type<CompatibleObjectType>>::value,
- typename BasicJsonType::object_t, CompatibleObjectType >::value;
-};
-
-template<typename BasicJsonType, typename T>
-struct is_basic_json_nested_type
-{
- static auto constexpr value = std::is_same<T, typename BasicJsonType::iterator>::value or
- std::is_same<T, typename BasicJsonType::const_iterator>::value or
- std::is_same<T, typename BasicJsonType::reverse_iterator>::value or
- std::is_same<T, typename BasicJsonType::const_reverse_iterator>::value;
-};
-
-template<class BasicJsonType, class CompatibleArrayType>
-struct is_compatible_array_type
-{
- static auto constexpr value =
- conjunction<negation<std::is_same<void, CompatibleArrayType>>,
- negation<is_compatible_object_type<
- BasicJsonType, CompatibleArrayType>>,
- negation<std::is_constructible<typename BasicJsonType::string_t,
- CompatibleArrayType>>,
- negation<is_basic_json_nested_type<BasicJsonType, CompatibleArrayType>>,
- has_value_type<CompatibleArrayType>,
- has_iterator<CompatibleArrayType>>::value;
-};
-
-template<bool, typename, typename>
-struct is_compatible_integer_type_impl : std::false_type {};
-
-template<typename RealIntegerType, typename CompatibleNumberIntegerType>
-struct is_compatible_integer_type_impl<true, RealIntegerType, CompatibleNumberIntegerType>
-{
- // 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
-{
- static constexpr auto value =
- is_compatible_integer_type_impl <
- std::is_integral<CompatibleNumberIntegerType>::value and
- not std::is_same<bool, CompatibleNumberIntegerType>::value,
- RealIntegerType, CompatibleNumberIntegerType >::value;
-};
-
-
-// trait checking if JSONSerializer<T>::from_json(json const&, udt&) exists
-template<typename BasicJsonType, typename T>
-struct has_from_json
-{
- private:
- // also check the return type of from_json
- template<typename U, typename = enable_if_t<std::is_same<void, decltype(uncvref_t<U>::from_json(
- std::declval<BasicJsonType>(), std::declval<T&>()))>::value>>
- static int detect(U&&);
- static void detect(...);
-
- public:
- static constexpr bool value = std::is_integral<decltype(
- detect(std::declval<typename BasicJsonType::template json_serializer<T, void>>()))>::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
-{
- private:
- template<typename U, typename =
- enable_if_t<std::is_same<T, decltype(uncvref_t<U>::from_json(std::declval<BasicJsonType>()))>::value>>
- static int detect(U&&);
- static void detect(...);
-
- public:
- static constexpr bool value = std::is_integral<decltype(detect(
- std::declval<typename BasicJsonType::template json_serializer<T, void>>()))>::value;
-};
-
-// This trait checks if BasicJsonType::json_serializer<T>::to_json exists
-template<typename BasicJsonType, typename T>
-struct has_to_json
-{
- private:
- template<typename U, typename = decltype(uncvref_t<U>::to_json(
- std::declval<BasicJsonType&>(), std::declval<T>()))>
- static int detect(U&&);
- static void detect(...);
-
- public:
- static constexpr bool value = std::is_integral<decltype(detect(
- std::declval<typename BasicJsonType::template json_serializer<T, void>>()))>::value;
-};
-
-
/////////////
// to_json //
/////////////