a class to store JSON values More...

#include <json.hpp>

Classes
class	const_iterator
	a const random access iterator for the basic_json class More...

class	iterator
	a mutable random access iterator for the basic_json class More...

class	json_pointer
	JSON Pointer. More...

class	json_reverse_iterator
	a template for a reverse iterator class More...

Public Types
enum	parse_event_t : uint8_t { parse_event_t::object_start, parse_event_t::object_end, parse_event_t::array_start, parse_event_t::array_end, parse_event_t::key, parse_event_t::value }
	JSON callback events. More...

using	parser_callback_t = std::function< bool(int depth, parse_event_t event, basic_json &parsed)>
	per-element parser callback type More...

enum	value_t : uint8_t { value_t::null, value_t::object, value_t::array, value_t::string, value_t::boolean, value_t::number_integer, value_t::number_unsigned, value_t::number_float, value_t::discarded }
	the JSON type enumeration More...

Static Public Member Functions
static allocator_type	get_allocator ()
	returns the allocator associated with the container More...

container types
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	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
using	object_t = ObjectType< StringType, basic_json, std::less< StringType >, 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...

constructors and destructors
static basic_json	array (std::initializer_list< basic_json > init=std::initializer_list< basic_json >())
	explicitly create an array from an initializer list More...

static basic_json	object (std::initializer_list< basic_json > init=std::initializer_list< basic_json >())
	explicitly create an object from an initializer list More...

	basic_json (const value_t value_type)
	create an empty value with a given type More...

	basic_json ()=default
	create a null object (implicitly) More...

	basic_json (std::nullptr_t) noexcept
	create a null object (explicitly) More...

	basic_json (const object_t &val)
	create an object (explicit) More...

template<class CompatibleObjectType , typename std::enable_if< std::is_constructible< typename object_t::key_type, typename CompatibleObjectType::key_type >::value and std::is_constructible< basic_json, typename CompatibleObjectType::mapped_type >::value, int >::type = 0>
	basic_json (const CompatibleObjectType &val)
	create an object (implicit) More...

	basic_json (const array_t &val)
	create an array (explicit) More...

template<class CompatibleArrayType , typename std::enable_if< not std::is_same< CompatibleArrayType, typename basic_json_t::iterator >::value and not std::is_same< CompatibleArrayType, typename basic_json_t::const_iterator >::value and not std::is_same< CompatibleArrayType, typename basic_json_t::reverse_iterator >::value and not std::is_same< CompatibleArrayType, typename basic_json_t::const_reverse_iterator >::value and not std::is_same< CompatibleArrayType, typename array_t::iterator >::value and not std::is_same< CompatibleArrayType, typename array_t::const_iterator >::value and std::is_constructible< basic_json, typename CompatibleArrayType::value_type >::value, int >::type = 0>
	basic_json (const CompatibleArrayType &val)
	create an array (implicit) More...

	basic_json (const string_t &val)
	create a string (explicit) More...

	basic_json (const typename string_t::value_type *val)
	create a string (explicit) More...

template<class CompatibleStringType , typename std::enable_if< std::is_constructible< string_t, CompatibleStringType >::value, int >::type = 0>
	basic_json (const CompatibleStringType &val)
	create a string (implicit) More...

	basic_json (boolean_t val) noexcept
	create a boolean (explicit) More...

template<typename T , typename std::enable_if< not(std::is_same< T, int >::value) and std::is_same< T, number_integer_t >::value , int >::type = 0>
	basic_json (const number_integer_t val) noexcept
	create an integer number (explicit) More...

	basic_json (const int val) noexcept
	create an integer number from an enum type (explicit) More...

template<typename CompatibleNumberIntegerType , typename std::enable_if< std::is_constructible< number_integer_t, CompatibleNumberIntegerType >::value and std::numeric_limits< CompatibleNumberIntegerType >::is_integer and std::numeric_limits< CompatibleNumberIntegerType >::is_signed, CompatibleNumberIntegerType >::type = 0>
	basic_json (const CompatibleNumberIntegerType val) noexcept
	create an integer number (implicit) More...

template<typename T , typename std::enable_if< not(std::is_same< T, int >::value) and std::is_same< T, number_unsigned_t >::value , int >::type = 0>
	basic_json (const number_unsigned_t val) noexcept
	create an unsigned integer number (explicit) More...

template<typename CompatibleNumberUnsignedType , typename std::enable_if< std::is_constructible< number_unsigned_t, CompatibleNumberUnsignedType >::value and std::numeric_limits< CompatibleNumberUnsignedType >::is_integer and !std::numeric_limits< CompatibleNumberUnsignedType >::is_signed, CompatibleNumberUnsignedType >::type = 0>
	basic_json (const CompatibleNumberUnsignedType val) noexcept
	create an unsigned number (implicit) More...

	basic_json (const number_float_t val) noexcept
	create a floating-point number (explicit) More...

template<typename CompatibleNumberFloatType , typename = typename std::enable_if< std::is_constructible<number_float_t, CompatibleNumberFloatType>::value and std::is_floating_point<CompatibleNumberFloatType>::value>::type>
	basic_json (const CompatibleNumberFloatType val) noexcept
	create an floating-point number (implicit) More...

	basic_json (std::initializer_list< basic_json > 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 or 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...

	basic_json (std::istream &i, parser_callback_t cb=nullptr)
	construct a JSON value given an input stream More...

	basic_json (const basic_json &other)
	copy constructor More...

	basic_json (basic_json &&other) noexcept
	move constructor More...

reference &	operator= (basic_json other) noexcept( std::is_nothrow_move_constructible< value_t >::value and std::is_nothrow_move_assignable< value_t >::value and std::is_nothrow_move_constructible< json_value >::value and std::is_nothrow_move_assignable< json_value >::value )
	copy assignment More...

	~basic_json ()
	destructor More...

object inspection
string_t	dump (const int indent=-1) 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_discarded () const noexcept
	return whether value is discarded More...

constexpr	operator value_t () const noexcept
	return the type of the JSON value (implicit) More...

value access
template<typename ValueType , typename std::enable_if< not std::is_pointer< ValueType >::value , int >::type = 0>
ValueType	get () const
	get a value (explicit) More...

template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value , int >::type = 0>
PointerType	get () noexcept
	get a pointer value (explicit) More...

template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value , int >::type = 0>
constexpr const PointerType	get () const noexcept
	get a pointer value (explicit) More...

template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value , int >::type = 0>
PointerType	get_ptr () noexcept
	get a pointer value (implicit) More...

template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value and std::is_const< typename std::remove_pointer< PointerType >::type >::value , int >::type = 0>
constexpr const PointerType	get_ptr () const noexcept
	get a pointer value (implicit) More...

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 and 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< not std::is_pointer< ValueType >::value and not std::is_same< ValueType, typename string_t::value_type >::value and not std::is_same< ValueType, std::initializer_list< typename string_t::value_type >>::value , int >::type = 0>
	operator ValueType () const
	get a value (implicit) More...

element access
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 , std::size_t n>
reference	operator[] (T *(&key)[n])
	access specified object element More...

template<typename T , std::size_t n>
const_reference	operator[] (T *(&key)[n]) 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< std::is_convertible< basic_json_t, ValueType >::value , int >::type = 0>
ValueType	value (const typename object_t::key_type &key, 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...

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 InteratorType , typename std::enable_if< std::is_same< InteratorType, typename basic_json_t::iterator >::value or std::is_same< InteratorType, typename basic_json_t::const_iterator >::value , int >::type = 0>
InteratorType	erase (InteratorType pos)
	remove element given an iterator More...

template<class InteratorType , typename std::enable_if< std::is_same< InteratorType, typename basic_json_t::iterator >::value or std::is_same< InteratorType, typename basic_json_t::const_iterator >::value , int >::type = 0>
InteratorType	erase (InteratorType first, InteratorType 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
iterator	find (typename object_t::key_type key)
	find an element in a JSON object More...

const_iterator	find (typename object_t::key_type key) const
	find an element in a JSON object More...

size_type	count (typename object_t::key_type key) const
	returns the number of occurrences of a key in a JSON object More...

iterators
static iteration_proxy< iterator >	iterator_wrapper (reference cont)
	wrapper to access iterator member functions in range-based for More...

static iteration_proxy< const_iterator >	iterator_wrapper (const_reference cont)
	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...

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...

modifiers
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 (std::initializer_list< basic_json > init)
	add an object to an object More...

reference	operator+= (std::initializer_list< basic_json > init)
	add an object to an object More...

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, std::initializer_list< basic_json > ilist)
	inserts elements More...

void	swap (reference other) noexcept( std::is_nothrow_move_constructible< value_t >::value and std::is_nothrow_move_assignable< value_t >::value and std::is_nothrow_move_constructible< json_value >::value and 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...

lexicographical comparison operators
bool	operator< (const value_t lhs, const value_t rhs) noexcept
	comparison operator for JSON types More...

bool	operator== (const_reference lhs, const_reference rhs) noexcept
	comparison: equal More...

bool	operator== (const_reference v, std::nullptr_t) noexcept
	comparison: equal More...

bool	operator== (std::nullptr_t, const_reference v) noexcept
	comparison: equal More...

bool	operator!= (const_reference lhs, const_reference rhs) noexcept
	comparison: not equal More...

bool	operator!= (const_reference v, std::nullptr_t) noexcept
	comparison: not equal More...

bool	operator!= (std::nullptr_t, const_reference v) noexcept
	comparison: not equal More...

bool	operator< (const_reference lhs, const_reference rhs) noexcept
	comparison: less than More...

bool	operator<= (const_reference lhs, const_reference rhs) noexcept
	comparison: less than or equal More...

bool	operator> (const_reference lhs, const_reference rhs) noexcept
	comparison: greater than More...

bool	operator>= (const_reference 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
static basic_json	parse (const string_t &s, parser_callback_t cb=nullptr)
	deserialize from string More...

static basic_json	parse (std::istream &i, parser_callback_t cb=nullptr)
	deserialize from stream More...

static basic_json	parse (std::istream &&i, parser_callback_t cb=nullptr)
	deserialize from stream More...

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...

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

basic_json	patch (const basic_json &patch) const
	applies a JSON 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>
class nlohmann::basic_json

Template Parameters

ObjectType	type for JSON objects (`std::map` by default; will be used in object_t)
ArrayType	type for JSON arrays (`std::vector` by default; will be used in array_t)
StringType	type for JSON strings and object keys (`std::string` by default; will be used in string_t)
BooleanType	type for JSON booleans (`bool` by default; will be used in boolean_t)
NumberIntegerType	type for JSON integer numbers (`int64_t` by default; will be used in number_integer_t)
NumberUnsignedType	type for JSON unsigned integer numbers (`uint64_t` by default; will be used in number_unsigned_t)
NumberFloatType	type for JSON floating-point numbers (`double` by default; will be used in number_float_t)
AllocatorType	type of the allocator to use (`std::allocator` by default)

Requirements

The class satisfies the following concept requirements:

Basic
- DefaultConstructible: JSON values can be default constructed. The result will be a JSON null value.
- MoveConstructible: A JSON value can be constructed from an rvalue argument.
- CopyConstructible: A JSON value can be copy-constructed from an lvalue expression.
- MoveAssignable: A JSON value van be assigned from an rvalue argument.
- CopyAssignable: A JSON value can be copy-assigned from an lvalue expression.
- Destructible: JSON values can be destructed.
Layout
- StandardLayoutType: JSON values have standard layout: All non-static data members are private and standard layout types, the class has no virtual functions or (virtual) base classes.
Library-wide
- EqualityComparable: JSON values can be compared with ==, see operator==(const_reference,const_reference).
- LessThanComparable: JSON values can be compared with <, see operator<(const_reference,const_reference).
- Swappable: Any JSON lvalue or rvalue of can be swapped with any lvalue or rvalue of other compatible types, using unqualified function call swap().
- NullablePointer: JSON values can be compared against std::nullptr_t objects which are used to model the null value.
Container
- Container: JSON values can be used like STL containers and provide iterator access.
- ReversibleContainer; JSON values can be used like STL containers and provide reverse iterator access.

See also: RFC 7159: The JavaScript Object Notation (JSON) Data Interchange Format

Since: version 1.0.0

Definition at line 187 of file json.hpp.

Classes

Public Types

Static Public Member Functions

container types

JSON value data types

constructors and destructors

object inspection

value access

element access

lookup

iterators

capacity

modifiers

lexicographical comparison operators

serialization

deserialization

JSON Pointer functions

JSON Patch functions

Detailed Description