JSON for Modern C++ 3.10.4
Public Types | Public Member Functions | Static Public Member Functions | Public Attributes | Friends | List of all members
nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > Class Template Reference

a class to store JSON values More...

#include <json.hpp>

Public Types

using cbor_tag_handler_t = detail::cbor_tag_handler_t
 how to treat CBOR tags More...
 
using error_handler_t = detail::error_handler_t
 how to treat decoding errors More...
 
using initializer_list_t = std::initializer_list< detail::json_ref< basic_json > >
 helper type for initializer lists of basic_json values More...
 
using input_format_t = detail::input_format_t
 
using json_pointer = ::nlohmann::json_pointer< basic_json >
 JSON Pointer, see nlohmann::json_pointer. More...
 
using json_sax_t = json_sax< basic_json >
 SAX interface type, see nlohmann::json_sax. More...
 
template<typename T , typename SFINAE >
using json_serializer = JSONSerializer< T, SFINAE >
 
using parse_event_t = detail::parse_event_t
 parser event types More...
 
using parser_callback_t = detail::parser_callback_t< basic_json >
 per-element parser callback type More...
 
using value_t = detail::value_t
 

Public Member Functions

const char * type_name () const noexcept
 return the type as string More...
 

Static Public Member Functions

static allocator_type get_allocator ()
 returns the allocator associated with the container More...
 
static basic_json meta ()
 returns version information on the library More...
 

Public Attributes

JSON_PRIVATE_UNLESS_TESTED __pad3__: value_t m_type = value_t::null
 
json_value m_value = {}
 the value of the current element More...
 

Friends

template<detail::value_t >
struct detail::external_constructor
 

exceptions

Classes to implement user-defined exceptions.

using exception = detail::exception
 general exception of the basic_json class More...
 
using parse_error = detail::parse_error
 exception indicating a parse error More...
 
using invalid_iterator = detail::invalid_iterator
 exception indicating errors with iterators More...
 
using type_error = detail::type_error
 exception indicating executing a member function with a wrong type More...
 
using out_of_range = detail::out_of_range
 exception indicating access out of the defined range More...
 
using other_error = detail::other_error
 exception indicating other library errors More...
 

container types

The canonic container types to use basic_json like any other STL container.

using value_type = basic_json
 the type of elements in a basic_json container More...
 
using reference = value_type &
 the type of an element reference More...
 
using const_reference = const value_type &
 the type of an element const reference More...
 
using difference_type = std::ptrdiff_t
 a type to represent differences between iterators More...
 
using size_type = std::size_t
 a type to represent container sizes More...
 
using allocator_type = AllocatorType< basic_json >
 the allocator type More...
 
using pointer = typename std::allocator_traits< allocator_type >::pointer
 the type of an element pointer More...
 
using const_pointer = typename std::allocator_traits< allocator_type >::const_pointer
 the type of an element const pointer More...
 
using iterator = iter_impl< basic_json >
 an iterator for a basic_json container More...
 
using const_iterator = iter_impl< const basic_json >
 a const iterator for a basic_json container More...
 
using reverse_iterator = json_reverse_iterator< typename basic_json::iterator >
 a reverse iterator for a basic_json container More...
 
using const_reverse_iterator = json_reverse_iterator< typename basic_json::const_iterator >
 a const reverse iterator for a basic_json container More...
 

JSON value data types

The data types to store a JSON value. These types are derived from the template arguments passed to class basic_json.

using object_comparator_t = std::less< StringType >
 
using object_t = ObjectType< StringType, basic_json, object_comparator_t, AllocatorType< std::pair< const StringType, basic_json > > >
 a type for an object More...
 
using array_t = ArrayType< basic_json, AllocatorType< basic_json > >
 a type for an array More...
 
using string_t = StringType
 a type for a string More...
 
using boolean_t = BooleanType
 a type for a boolean More...
 
using number_integer_t = NumberIntegerType
 a type for a number (integer) More...
 
using number_unsigned_t = NumberUnsignedType
 a type for a number (unsigned) More...
 
using number_float_t = NumberFloatType
 a type for a number (floating-point) More...
 
using binary_t = nlohmann::byte_container_with_subtype< BinaryType >
 a type for a packed binary type More...
 

modifiers

void swap (reference left, reference right) noexcept(std::is_nothrow_move_constructible< value_t >::value &&std::is_nothrow_move_assignable< value_t >::value &&std::is_nothrow_move_constructible< json_value >::value &&std::is_nothrow_move_assignable< json_value >::value)
 exchanges the values More...
 
void clear () noexcept
 clears the contents More...
 
void push_back (basic_json &&val)
 add an object to an array More...
 
reference operator+= (basic_json &&val)
 add an object to an array More...
 
void push_back (const basic_json &val)
 add an object to an array More...
 
reference operator+= (const basic_json &val)
 add an object to an array More...
 
void push_back (const typename object_t::value_type &val)
 add an object to an object More...
 
reference operator+= (const typename object_t::value_type &val)
 add an object to an object More...
 
void push_back (initializer_list_t init)
 add an object to an object More...
 
reference operator+= (initializer_list_t init)
 add an object to an object More...
 
template<class... Args>
reference emplace_back (Args &&... args)
 add an object to an array More...
 
template<class... Args>
std::pair< iterator, bool > emplace (Args &&... args)
 add an object to an object if key does not exist More...
 
template<typename... Args>
iterator insert_iterator (const_iterator pos, Args &&... args)
 
iterator insert (const_iterator pos, const basic_json &val)
 inserts element More...
 
iterator insert (const_iterator pos, basic_json &&val)
 inserts element More...
 
iterator insert (const_iterator pos, size_type cnt, const basic_json &val)
 inserts elements More...
 
iterator insert (const_iterator pos, const_iterator first, const_iterator last)
 inserts elements More...
 
iterator insert (const_iterator pos, initializer_list_t ilist)
 inserts elements More...
 
void insert (const_iterator first, const_iterator last)
 inserts elements More...
 
void update (const_reference j)
 updates a JSON object from another object, overwriting existing keys More...
 
void update (const_iterator first, const_iterator last)
 updates a JSON object from another object, overwriting existing keys More...
 
void swap (reference other) noexcept(std::is_nothrow_move_constructible< value_t >::value &&std::is_nothrow_move_assignable< value_t >::value &&std::is_nothrow_move_constructible< json_value >::value &&std::is_nothrow_move_assignable< json_value >::value)
 exchanges the values More...
 
void swap (array_t &other)
 exchanges the values More...
 
void swap (object_t &other)
 exchanges the values More...
 
void swap (string_t &other)
 exchanges the values More...
 
void swap (binary_t &other)
 exchanges the values More...
 
void swap (typename binary_t::container_type &other)
 exchanges the values More...
 

lexicographical comparison operators

bool operator== (const_reference lhs, const_reference rhs) noexcept
 comparison: equal More...
 
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool operator== (const_reference lhs, ScalarType rhs) noexcept
 comparison: equal More...
 
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool operator== (ScalarType lhs, const_reference rhs) noexcept
 comparison: equal More...
 
bool operator!= (const_reference lhs, const_reference rhs) noexcept
 comparison: not equal More...
 
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool operator!= (const_reference lhs, ScalarType rhs) noexcept
 comparison: not equal More...
 
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool operator!= (ScalarType lhs, const_reference rhs) noexcept
 comparison: not equal More...
 
bool operator< (const_reference lhs, const_reference rhs) noexcept
 comparison: less than More...
 
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool operator< (const_reference lhs, ScalarType rhs) noexcept
 comparison: less than More...
 
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool operator< (ScalarType lhs, const_reference rhs) noexcept
 comparison: less than More...
 
bool operator<= (const_reference lhs, const_reference rhs) noexcept
 comparison: less than or equal More...
 
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool operator<= (const_reference lhs, ScalarType rhs) noexcept
 comparison: less than or equal More...
 
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool operator<= (ScalarType lhs, const_reference rhs) noexcept
 comparison: less than or equal More...
 
bool operator> (const_reference lhs, const_reference rhs) noexcept
 comparison: greater than More...
 
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool operator> (const_reference lhs, ScalarType rhs) noexcept
 comparison: greater than More...
 
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool operator> (ScalarType lhs, const_reference rhs) noexcept
 comparison: greater than More...
 
bool operator>= (const_reference lhs, const_reference rhs) noexcept
 comparison: greater than or equal More...
 
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool operator>= (const_reference lhs, ScalarType rhs) noexcept
 comparison: greater than or equal More...
 
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
bool operator>= (ScalarType lhs, const_reference rhs) noexcept
 comparison: greater than or equal More...
 

serialization

std::ostream & operator<< (std::ostream &o, const basic_json &j)
 serialize to stream More...
 
std::ostream & operator>> (const basic_json &j, std::ostream &o)
 serialize to stream More...
 

deserialization

std::istream & operator<< (basic_json &j, std::istream &i)
 deserialize from stream More...
 
std::istream & operator>> (std::istream &i, basic_json &j)
 deserialize from stream More...
 
template<typename InputType >
static basic_json parse (InputType &&i, const parser_callback_t cb=nullptr, const bool allow_exceptions=true, const bool ignore_comments=false)
 deserialize from a compatible input More...
 
template<typename IteratorType >
static basic_json parse (IteratorType first, IteratorType last, const parser_callback_t cb=nullptr, const bool allow_exceptions=true, const bool ignore_comments=false)
 deserialize from a pair of character iterators More...
 
static basic_json parse (detail::span_input_adapter &&i, const parser_callback_t cb=nullptr, const bool allow_exceptions=true, const bool ignore_comments=false)
 
template<typename InputType >
static bool accept (InputType &&i, const bool ignore_comments=false)
 check if the input is valid JSON More...
 
template<typename IteratorType >
static bool accept (IteratorType first, IteratorType last, const bool ignore_comments=false)
 
static bool accept (detail::span_input_adapter &&i, const bool ignore_comments=false)
 
template<typename InputType , typename SAX >
static bool sax_parse (InputType &&i, SAX *sax, input_format_t format=input_format_t::json, const bool strict=true, const bool ignore_comments=false)
 generate SAX events More...
 
template<class IteratorType , class SAX >
static bool sax_parse (IteratorType first, IteratorType last, SAX *sax, input_format_t format=input_format_t::json, const bool strict=true, const bool ignore_comments=false)
 
template<typename SAX >
static bool sax_parse (detail::span_input_adapter &&i, SAX *sax, input_format_t format=input_format_t::json, const bool strict=true, const bool ignore_comments=false)
 

value access

Direct access to the stored value of a JSON value.

template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value, int >::type = 0>
auto get_ptr () noexcept -> decltype(std::declval< basic_json_t & >().get_impl_ptr(std::declval< PointerType >()))
 get a pointer value (implicit) More...
 
template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value &&std::is_const< typename std::remove_pointer< PointerType >::type >::value, int >::type = 0>
constexpr auto get_ptr () const noexcept -> decltype(std::declval< const basic_json_t & >().get_impl_ptr(std::declval< PointerType >()))
 get a pointer value (implicit) More...
 
template<typename ValueTypeCV , typename ValueType = detail::uncvref_t<ValueTypeCV>>
auto get () const noexcept(noexcept(std::declval< const basic_json_t & >().template get_impl< ValueType >(detail::priority_tag< 4 > {}))) -> decltype(std::declval< const basic_json_t & >().template get_impl< ValueType >(detail::priority_tag< 4 > {}))
 get a (pointer) value (explicit) More...
 
template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value, int >::type = 0>
auto get () noexcept -> decltype(std::declval< basic_json_t & >().template get_ptr< PointerType >())
 get a pointer value (explicit) More...
 
template<typename ValueType , detail::enable_if_t< !detail::is_basic_json< ValueType >::value &&detail::has_from_json< basic_json_t, ValueType >::value, int > = 0>
ValueType & get_to (ValueType &v) const noexcept(noexcept(JSONSerializer< ValueType >::from_json(std::declval< const basic_json_t & >(), v)))
 get a value (explicit) More...
 
template<typename ValueType , detail::enable_if_t< detail::is_basic_json< ValueType >::value, int > = 0>
ValueType & get_to (ValueType &v) const
 
template<typename T , std::size_t N, typename Array = T (&)[N], detail::enable_if_t< detail::has_from_json< basic_json_t, Array >::value, int > = 0>
Array get_to (T(&v)[N]) const noexcept(noexcept(JSONSerializer< Array >::from_json(std::declval< const basic_json_t & >(), v)))
 
template<typename ReferenceType , typename std::enable_if< std::is_reference< ReferenceType >::value, int >::type = 0>
ReferenceType get_ref ()
 get a reference value (implicit) More...
 
template<typename ReferenceType , typename std::enable_if< std::is_reference< ReferenceType >::value &&std::is_const< typename std::remove_reference< ReferenceType >::type >::value, int >::type = 0>
ReferenceType get_ref () const
 get a reference value (implicit) More...
 
template<typename ValueType , typename std::enable_if< detail::conjunction< detail::negation< std::is_pointer< ValueType > >, detail::negation< std::is_same< ValueType, detail::json_ref< basic_json > > >, detail::negation< std::is_same< ValueType, typename string_t::value_type > >, detail::negation< detail::is_basic_json< ValueType > >, detail::negation< std::is_same< ValueType, std::initializer_list< typename string_t::value_type > > >, detail::is_detected_lazy< detail::get_template_function, const basic_json_t &, ValueType > >::value, int >::type = 0>
JSON_EXPLICIT operator ValueType () const
 get a value (implicit) More...
 
binary_tget_binary ()
 
const binary_tget_binary () const
 

constructors and destructors

Constructors of class basic_json, copy/move constructor, copy assignment, static functions creating objects, and the destructor.

static basic_json binary (const typename binary_t::container_type &init)
 explicitly create a binary array (without subtype) More...
 
static basic_json binary (const typename binary_t::container_type &init, typename binary_t::subtype_type subtype)
 explicitly create a binary array (with subtype) More...
 
static basic_json binary (typename binary_t::container_type &&init)
 explicitly create a binary array (without subtype) More...
 
static basic_json binary (typename binary_t::container_type &&init, typename binary_t::subtype_type subtype)
 explicitly create a binary array (with subtype) More...
 
static basic_json array (initializer_list_t init={})
 explicitly create an array from an initializer list More...
 
static basic_json object (initializer_list_t init={})
 explicitly create an object from an initializer list More...
 
 basic_json (const value_t v)
 create an empty value with a given type More...
 
 basic_json (std::nullptr_t=nullptr) noexcept
 create a null object More...
 
template<typename CompatibleType , typename U = detail::uncvref_t<CompatibleType>, detail::enable_if_t< !detail::is_basic_json< U >::value &&detail::is_compatible_type< basic_json_t, U >::value, int > = 0>
 basic_json (CompatibleType &&val) noexcept(noexcept(//NOLINT(bugprone-forwarding-reference-overload, bugprone-exception-escape) JSONSerializer< U >::to_json(std::declval< basic_json_t & >(), std::forward< CompatibleType >(val))))
 create a JSON value More...
 
template<typename BasicJsonType , detail::enable_if_t< detail::is_basic_json< BasicJsonType >::value &&!std::is_same< basic_json, BasicJsonType >::value, int > = 0>
 basic_json (const BasicJsonType &val)
 create a JSON value from an existing one More...
 
 basic_json (initializer_list_t init, bool type_deduction=true, value_t manual_type=value_t::array)
 create a container (array or object) from an initializer list More...
 
 basic_json (size_type cnt, const basic_json &val)
 construct an array with count copies of given value More...
 
template<class InputIT , typename std::enable_if< std::is_same< InputIT, typename basic_json_t::iterator >::value||std::is_same< InputIT, typename basic_json_t::const_iterator >::value, int >::type = 0>
 basic_json (InputIT first, InputIT last)
 construct a JSON container given an iterator range More...
 
template<typename JsonRef , detail::enable_if_t< detail::conjunction< detail::is_json_ref< JsonRef >, std::is_same< typename JsonRef::value_type, basic_json > >::value, int > = 0>
 basic_json (const JsonRef &ref)
 
 basic_json (const basic_json &other)
 copy constructor More...
 
 basic_json (basic_json &&other) noexcept
 move constructor More...
 
basic_jsonoperator= (basic_json other) noexcept(std::is_nothrow_move_constructible< value_t >::value &&std::is_nothrow_move_assignable< value_t >::value &&std::is_nothrow_move_constructible< json_value >::value &&std::is_nothrow_move_assignable< json_value >::value)
 copy assignment More...
 
 ~basic_json () noexcept
 destructor More...
 

iterators

static iteration_proxy< iteratoriterator_wrapper (reference ref) noexcept
 wrapper to access iterator member functions in range-based for More...
 
static iteration_proxy< const_iteratoriterator_wrapper (const_reference ref) noexcept
 wrapper to access iterator member functions in range-based for More...
 
iterator begin () noexcept
 returns an iterator to the first element More...
 
const_iterator begin () const noexcept
 returns a const iterator to the first element More...
 
const_iterator cbegin () const noexcept
 returns a const iterator to the first element More...
 
iterator end () noexcept
 returns an iterator to one past the last element More...
 
const_iterator end () const noexcept
 returns a const iterator to one past the last element More...
 
const_iterator cend () const noexcept
 returns a const iterator to one past the last element More...
 
reverse_iterator rbegin () noexcept
 returns an iterator to the reverse-beginning More...
 
const_reverse_iterator rbegin () const noexcept
 returns a const reverse iterator to the last element More...
 
reverse_iterator rend () noexcept
 returns an iterator to the reverse-end More...
 
const_reverse_iterator rend () const noexcept
 returns a const reverse iterator to one before the first More...
 
const_reverse_iterator crbegin () const noexcept
 returns a const reverse iterator to the last element More...
 
const_reverse_iterator crend () const noexcept
 returns a const reverse iterator to one before the first More...
 
iteration_proxy< iteratoritems () noexcept
 helper to access iterator member functions in range-based for More...
 
iteration_proxy< const_iteratoritems () const noexcept
 helper to access iterator member functions in range-based for More...
 

binary serialization/deserialization support

static std::vector< std::uint8_t > to_cbor (const basic_json &j)
 create a CBOR serialization of a given JSON value More...
 
static void to_cbor (const basic_json &j, detail::output_adapter< std::uint8_t > o)
 
static void to_cbor (const basic_json &j, detail::output_adapter< char > o)
 
static std::vector< std::uint8_t > to_msgpack (const basic_json &j)
 create a MessagePack serialization of a given JSON value More...
 
static void to_msgpack (const basic_json &j, detail::output_adapter< std::uint8_t > o)
 
static void to_msgpack (const basic_json &j, detail::output_adapter< char > o)
 
static std::vector< std::uint8_t > to_ubjson (const basic_json &j, const bool use_size=false, const bool use_type=false)
 create a UBJSON serialization of a given JSON value More...
 
static void to_ubjson (const basic_json &j, detail::output_adapter< std::uint8_t > o, const bool use_size=false, const bool use_type=false)
 
static void to_ubjson (const basic_json &j, detail::output_adapter< char > o, const bool use_size=false, const bool use_type=false)
 
static std::vector< std::uint8_t > to_bson (const basic_json &j)
 Serializes the given JSON object j to BSON and returns a vector containing the corresponding BSON-representation. More...
 
static void to_bson (const basic_json &j, detail::output_adapter< std::uint8_t > o)
 Serializes the given JSON object j to BSON and forwards the corresponding BSON-representation to the given output_adapter o. More...
 
static void to_bson (const basic_json &j, detail::output_adapter< char > o)
 Serializes the given JSON object j to BSON and forwards the corresponding BSON-representation to the given output_adapter o. More...
 
template<typename InputType >
static basic_json from_cbor (InputType &&i, const bool strict=true, const bool allow_exceptions=true, const cbor_tag_handler_t tag_handler=cbor_tag_handler_t::error)
 create a JSON value from an input in CBOR format More...
 
template<typename IteratorType >
static basic_json from_cbor (IteratorType first, IteratorType last, const bool strict=true, const bool allow_exceptions=true, const cbor_tag_handler_t tag_handler=cbor_tag_handler_t::error)
 create a JSON value from an input in CBOR format More...
 
template<typename T >
static basic_json from_cbor (const T *ptr, std::size_t len, const bool strict=true, const bool allow_exceptions=true, const cbor_tag_handler_t tag_handler=cbor_tag_handler_t::error)
 
static basic_json from_cbor (detail::span_input_adapter &&i, const bool strict=true, const bool allow_exceptions=true, const cbor_tag_handler_t tag_handler=cbor_tag_handler_t::error)
 
template<typename InputType >
static basic_json from_msgpack (InputType &&i, const bool strict=true, const bool allow_exceptions=true)
 create a JSON value from an input in MessagePack format More...
 
template<typename IteratorType >
static basic_json from_msgpack (IteratorType first, IteratorType last, const bool strict=true, const bool allow_exceptions=true)
 create a JSON value from an input in MessagePack format More...
 
template<typename T >
static basic_json from_msgpack (const T *ptr, std::size_t len, const bool strict=true, const bool allow_exceptions=true)
 
static basic_json from_msgpack (detail::span_input_adapter &&i, const bool strict=true, const bool allow_exceptions=true)
 
template<typename InputType >
static basic_json from_ubjson (InputType &&i, const bool strict=true, const bool allow_exceptions=true)
 create a JSON value from an input in UBJSON format More...
 
template<typename IteratorType >
static basic_json from_ubjson (IteratorType first, IteratorType last, const bool strict=true, const bool allow_exceptions=true)
 create a JSON value from an input in UBJSON format More...
 
template<typename T >
static basic_json from_ubjson (const T *ptr, std::size_t len, const bool strict=true, const bool allow_exceptions=true)
 
static basic_json from_ubjson (detail::span_input_adapter &&i, const bool strict=true, const bool allow_exceptions=true)
 
template<typename InputType >
static basic_json from_bson (InputType &&i, const bool strict=true, const bool allow_exceptions=true)
 Create a JSON value from an input in BSON format. More...
 
template<typename IteratorType >
static basic_json from_bson (IteratorType first, IteratorType last, const bool strict=true, const bool allow_exceptions=true)
 Create a JSON value from an input in BSON format. More...
 
template<typename T >
static basic_json from_bson (const T *ptr, std::size_t len, const bool strict=true, const bool allow_exceptions=true)
 
static basic_json from_bson (detail::span_input_adapter &&i, const bool strict=true, const bool allow_exceptions=true)
 

JSON Patch functions

static basic_json diff (const basic_json &source, const basic_json &target, const std::string &path="")
 creates a diff as a JSON patch More...
 
basic_json patch (const basic_json &json_patch) const
 applies a JSON patch More...
 

object inspection

Functions to inspect the type of a JSON value.

string_t dump (const int indent=-1, const char indent_char=' ', const bool ensure_ascii=false, const error_handler_t error_handler=error_handler_t::strict) const
 serialization More...
 
constexpr value_t type () const noexcept
 return the type of the JSON value (explicit) More...
 
constexpr bool is_primitive () const noexcept
 return whether type is primitive More...
 
constexpr bool is_structured () const noexcept
 return whether type is structured More...
 
constexpr bool is_null () const noexcept
 return whether value is null More...
 
constexpr bool is_boolean () const noexcept
 return whether value is a boolean More...
 
constexpr bool is_number () const noexcept
 return whether value is a number More...
 
constexpr bool is_number_integer () const noexcept
 return whether value is an integer number More...
 
constexpr bool is_number_unsigned () const noexcept
 return whether value is an unsigned integer number More...
 
constexpr bool is_number_float () const noexcept
 return whether value is a floating-point number More...
 
constexpr bool is_object () const noexcept
 return whether value is an object More...
 
constexpr bool is_array () const noexcept
 return whether value is an array More...
 
constexpr bool is_string () const noexcept
 return whether value is a string More...
 
constexpr bool is_binary () const noexcept
 return whether value is a binary array More...
 
constexpr bool is_discarded () const noexcept
 return whether value is discarded More...
 
constexpr operator value_t () const noexcept
 return the type of the JSON value (implicit) More...
 

element access

Access to the JSON value.

reference at (size_type idx)
 access specified array element with bounds checking More...
 
const_reference at (size_type idx) const
 access specified array element with bounds checking More...
 
reference at (const typename object_t::key_type &key)
 access specified object element with bounds checking More...
 
const_reference at (const typename object_t::key_type &key) const
 access specified object element with bounds checking More...
 
reference operator[] (size_type idx)
 access specified array element More...
 
const_reference operator[] (size_type idx) const
 access specified array element More...
 
reference operator[] (const typename object_t::key_type &key)
 access specified object element More...
 
const_reference operator[] (const typename object_t::key_type &key) const
 read-only access specified object element More...
 
template<typename T >
reference operator[] (T *key)
 access specified object element More...
 
template<typename T >
const_reference operator[] (T *key) const
 read-only access specified object element More...
 
template<class ValueType , typename std::enable_if< detail::is_getable< basic_json_t, ValueType >::value &&!std::is_same< value_t, ValueType >::value, int >::type = 0>
ValueType value (const typename object_t::key_type &key, const ValueType &default_value) const
 access specified object element with default value More...
 
string_t value (const typename object_t::key_type &key, const char *default_value) const
 overload for a default value of type const char* More...
 
template<class ValueType , typename std::enable_if< detail::is_getable< basic_json_t, ValueType >::value, int >::type = 0>
ValueType value (const json_pointer &ptr, const ValueType &default_value) const
 access specified object element via JSON Pointer with default value More...
 
string_t value (const json_pointer &ptr, const char *default_value) const
 overload for a default value of type const char* More...
 
reference front ()
 access the first element More...
 
const_reference front () const
 access the first element More...
 
reference back ()
 access the last element More...
 
const_reference back () const
 access the last element More...
 
template<class IteratorType , typename std::enable_if< std::is_same< IteratorType, typename basic_json_t::iterator >::value||std::is_same< IteratorType, typename basic_json_t::const_iterator >::value, int >::type = 0>
IteratorType erase (IteratorType pos)
 remove element given an iterator More...
 
template<class IteratorType , typename std::enable_if< std::is_same< IteratorType, typename basic_json_t::iterator >::value||std::is_same< IteratorType, typename basic_json_t::const_iterator >::value, int >::type = 0>
IteratorType erase (IteratorType first, IteratorType last)
 remove elements given an iterator range More...
 
size_type erase (const typename object_t::key_type &key)
 remove element from a JSON object given a key More...
 
void erase (const size_type idx)
 remove element from a JSON array given an index More...
 

lookup

template<typename KeyT >
iterator find (KeyT &&key)
 find an element in a JSON object More...
 
template<typename KeyT >
const_iterator find (KeyT &&key) const
 find an element in a JSON object More...
 
template<typename KeyT >
size_type count (KeyT &&key) const
 returns the number of occurrences of a key in a JSON object More...
 
template<typename KeyT , typename std::enable_if< !std::is_same< typename std::decay< KeyT >::type, json_pointer >::value, int >::type = 0>
bool contains (KeyT &&key) const
 check the existence of an element in a JSON object More...
 
bool contains (const json_pointer &ptr) const
 check the existence of an element in a JSON object given a JSON pointer More...
 

capacity

bool empty () const noexcept
 checks whether the container is empty. More...
 
size_type size () const noexcept
 returns the number of elements More...
 
size_type max_size () const noexcept
 returns the maximum possible number of elements More...
 

JSON Pointer functions

reference operator[] (const json_pointer &ptr)
 access specified element via JSON Pointer More...
 
const_reference operator[] (const json_pointer &ptr) const
 access specified element via JSON Pointer More...
 
reference at (const json_pointer &ptr)
 access specified element via JSON Pointer More...
 
const_reference at (const json_pointer &ptr) const
 access specified element via JSON Pointer More...
 
basic_json flatten () const
 return flattened JSON value More...
 
basic_json unflatten () const
 unflatten a previously flattened JSON value More...
 

JSON Merge Patch functions

void merge_patch (const basic_json &apply_patch)
 applies a JSON Merge Patch More...
 

Detailed Description

template<template< typename U, typename V, typename... Args > class ObjectType = std::map, template< typename U, typename... Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>
class nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >
Template Parameters
ObjectTypetype for JSON objects (std::map by default; will be used in object_t)
ArrayTypetype for JSON arrays (std::vector by default; will be used in array_t)
StringTypetype for JSON strings and object keys (std::string by default; will be used in string_t)
BooleanTypetype for JSON booleans (bool by default; will be used in boolean_t)
NumberIntegerTypetype for JSON integer numbers (int64_t by default; will be used in number_integer_t)
NumberUnsignedTypetype for JSON unsigned integer numbers (uint64_t by default; will be used in number_unsigned_t)
NumberFloatTypetype for JSON floating-point numbers (double by default; will be used in number_float_t)
BinaryTypetype for packed binary data for compatibility with binary serialization formats (std::vector<std::uint8_t> by default; will be used in binary_t)
AllocatorTypetype of the allocator to use (std::allocator by default)
JSONSerializerthe serializer to resolve internal calls to to_json() and from_json() (adl_serializer by default)
Requirements
The class satisfies the following concept requirements:
Invariant
The member variables m_value and m_type have the following relationship:
  • If m_type == value_t::object, then m_value.object != nullptr.
  • If m_type == value_t::array, then m_value.array != nullptr.
  • If m_type == value_t::string, then m_value.string != nullptr. The invariants are checked by member function assert_invariant().
See also
RFC 8259: The JavaScript Object Notation (JSON) Data Interchange Format
Since
version 1.0.0

Definition at line 17677 of file json.hpp.