Represents a JSON value. More...

#include <value.h>

Public Types
using	Members = std::vector< String >

using	iterator = ValueIterator

using	const_iterator = ValueConstIterator

using	UInt = Json::UInt

using	Int = Json::Int

using	UInt64 = Json::UInt64

using	Int64 = Json::Int64

using	LargestInt = Json::LargestInt

using	LargestUInt = Json::LargestUInt

using	ArrayIndex = Json::ArrayIndex

using	value_type = std::string

typedef std::map< CZString, Value >	ObjectValues

Public Member Functions
	Value (ValueType type=nullValue)
	Create a default Value of the given type. More...

	Value (Int value)

	Value (UInt value)

	Value (Int64 value)

	Value (UInt64 value)

	Value (double value)

	Value (const char *value)
	Copy til first 0. (NULL causes to seg-fault.) More...

	Value (const char begin, const char end)
	Copy all, incl zeroes. More...

	Value (const StaticString &value)
	Constructs a value from a static string. More...

	Value (const String &value)

	Value (bool value)

	Value (std::nullptr_t ptr)=delete

	Value (const Value &other)

	Value (Value &&other) noexcept

Value &	operator= (const Value &other)

Value &	operator= (Value &&other) noexcept

void	swap (Value &other)
	Swap everything. More...

void	swapPayload (Value &other)
	Swap values but leave comments and source offsets in place. More...

void	copy (const Value &other)
	copy everything. More...

void	copyPayload (const Value &other)
	copy values but leave comments and source offsets in place. More...

ValueType	type () const

bool	operator< (const Value &other) const
	Compare payload only, not comments etc. More...

bool	operator<= (const Value &other) const

bool	operator>= (const Value &other) const

bool	operator> (const Value &other) const

bool	operator== (const Value &other) const

bool	operator!= (const Value &other) const

int	compare (const Value &other) const

const char *	asCString () const
	Embedded zeroes could cause you trouble! More...

String	asString () const
	Embedded zeroes are possible. More...

bool	getString (char const begin, char const end) const
	Get raw char* of string-value. More...

Int	asInt () const

UInt	asUInt () const

Int64	asInt64 () const

UInt64	asUInt64 () const

LargestInt	asLargestInt () const

LargestUInt	asLargestUInt () const

float	asFloat () const

double	asDouble () const

bool	asBool () const

bool	isNull () const

bool	isBool () const

bool	isInt () const

bool	isInt64 () const

bool	isUInt () const

bool	isUInt64 () const

bool	isIntegral () const

bool	isDouble () const

bool	isNumeric () const

bool	isString () const

bool	isArray () const

bool	isObject () const

template<typename T >
T	as () const JSONCPP_TEMPLATE_DELETE
	The `as<T>` and `is<T>` member function templates and specializations. More...

template<typename T >
bool	is () const JSONCPP_TEMPLATE_DELETE

bool	isConvertibleTo (ValueType other) const

ArrayIndex	size () const
	Number of values in array or object. More...

bool	empty () const
	Return true if empty array, empty object, or null; otherwise, false. More...

	operator bool () const
	Return !isNull() More...

void	clear ()
	Remove all object members and array elements. More...

void	resize (ArrayIndex newSize)
	Resize the array to newSize elements. More...

Value	get (ArrayIndex index, const Value &defaultValue) const
	If the array contains at least index+1 elements, returns the element value, otherwise returns defaultValue. More...

bool	isValidIndex (ArrayIndex index) const
	Return true if index < size(). More...

Value &	append (const Value &value)
	Append value to array at the end. More...

Value &	append (Value &&value)

bool	insert (ArrayIndex index, const Value &newValue)
	Insert value in array at specific index. More...

bool	insert (ArrayIndex index, Value &&newValue)

Value &	operator[] (const char *key)
	Access an object value by name, create a null member if it does not exist. More...

const Value &	operator[] (const char *key) const
	Access an object value by name, returns null if there is no member with that name. More...

Value &	operator[] (const String &key)
	Access an object value by name, create a null member if it does not exist. More...

const Value &	operator[] (const String &key) const
	Access an object value by name, returns null if there is no member with that name. More...

Value &	operator[] (const StaticString &key)
	Access an object value by name, create a null member if it does not exist. More...

Value	get (const char *key, const Value &defaultValue) const
	Return the member named key if it exist, defaultValue otherwise. More...

Value	get (const char begin, const char end, const Value &defaultValue) const
	Return the member named key if it exist, defaultValue otherwise. More...

Value	get (const String &key, const Value &defaultValue) const
	Return the member named key if it exist, defaultValue otherwise. More...

Value const *	find (char const begin, char const end) const
	Most general and efficient version of isMember()const, get()const, and operator[]const. More...

Value *	demand (char const begin, char const end)
	Most general and efficient version of object-mutators. More...

void	removeMember (const char *key)
	Remove and return the named member. More...

void	removeMember (const String &key)
	Same as removeMember(const char*) More...

bool	removeMember (const char key, Value removed)
	Same as removeMember(const char* begin, const char* end, Value* removed), but 'key' is null-terminated. More...

bool	removeMember (String const &key, Value *removed)
	Remove the named map member. More...

bool	removeMember (const char begin, const char end, Value *removed)
	Same as removeMember(String const& key, Value* removed) More...

bool	removeIndex (ArrayIndex index, Value *removed)
	Remove the indexed array element. More...

bool	isMember (const char *key) const
	Return true if the object has a member named key. More...

bool	isMember (const String &key) const
	Return true if the object has a member named key. More...

bool	isMember (const char begin, const char end) const
	Same as isMember(String const& key)const. More...

Members	getMemberNames () const
	Return a list of the member names. More...

void	setComment (const char *comment, CommentPlacement placement)

void	setComment (const char *comment, size_t len, CommentPlacement placement)
	Comments must be //... or /* ... */. More...

void	setComment (String comment, CommentPlacement placement)
	Comments must be //... or /* ... */. More...

bool	hasComment (CommentPlacement placement) const

String	getComment (CommentPlacement placement) const
	Include delimiters and embedded newlines. More...

String	toStyledString () const

const_iterator	begin () const

const_iterator	end () const

iterator	begin ()

iterator	end ()

void	setOffsetStart (ptrdiff_t start)

void	setOffsetLimit (ptrdiff_t limit)

ptrdiff_t	getOffsetStart () const

ptrdiff_t	getOffsetLimit () const

template<>
bool	as () const

template<>
bool	is () const

template<>
Int	as () const

template<>
bool	is () const

template<>
UInt	as () const

template<>
bool	is () const

template<>
Int64	as () const

template<>
bool	is () const

template<>
UInt64	as () const

template<>
bool	is () const

template<>
double	as () const

template<>
bool	is () const

template<>
String	as () const

template<>
bool	is () const

template<>
float	as () const
	These `as` specializations are type conversions, and do not have a corresponding `is`. More...

template<>
const char *	as () const


Value &	operator[] (ArrayIndex index)

Value &	operator[] (int index)


const Value &	operator[] (ArrayIndex index) const

const Value &	operator[] (int index) const

Static Public Member Functions
static Value const &	nullSingleton ()

Static Public Attributes
static const Value &	null

static const Value &	nullRef

static constexpr LargestInt	minLargestInt
	Minimum signed integer value that can be stored in a Json::Value. More...

static constexpr LargestInt	maxLargestInt = LargestInt(LargestUInt(-1) / 2)
	Maximum signed integer value that can be stored in a Json::Value. More...

static constexpr LargestUInt	maxLargestUInt = LargestUInt(-1)
	Maximum unsigned integer value that can be stored in a Json::Value. More...

static constexpr Int	minInt = Int(~(UInt(-1) / 2))
	Minimum signed int value that can be stored in a Json::Value. More...

static constexpr Int	maxInt = Int(UInt(-1) / 2)
	Maximum signed int value that can be stored in a Json::Value. More...

static constexpr UInt	maxUInt = UInt(-1)
	Maximum unsigned int value that can be stored in a Json::Value. More...

static constexpr Int64	minInt64 = Int64(~(UInt64(-1) / 2))
	Minimum signed 64 bits int value that can be stored in a Json::Value. More...

static constexpr Int64	maxInt64 = Int64(UInt64(-1) / 2)
	Maximum signed 64 bits int value that can be stored in a Json::Value. More...

static constexpr UInt64	maxUInt64 = UInt64(-1)
	Maximum unsigned 64 bits int value that can be stored in a Json::Value. More...

static constexpr UInt	defaultRealPrecision = 17
	Default precision for real value for string representation. More...

static constexpr double	maxUInt64AsDouble = 18446744073709551615.0

Private Member Functions
void	setType (ValueType v)

bool	isAllocated () const

void	setIsAllocated (bool v)

void	initBasic (ValueType type, bool allocated=false)

void	dupPayload (const Value &other)

void	releasePayload ()

void	dupMeta (const Value &other)

Value &	resolveReference (const char *key)

Value &	resolveReference (const char key, const char end)

Private Attributes
union Json::Value::ValueHolder	value_

struct {
unsigned int value_type_: 8

unsigned int allocated_: 1

}	bits_

Comments	comments_

ptrdiff_t	start_

ptrdiff_t	limit_

Friends
class	ValueIteratorBase

Detailed Description

Represents a JSON value.

This class is a discriminated union wrapper that can represents a:

signed integer [range: Value::minInt - Value::maxInt]
unsigned integer (range: 0 - Value::maxUInt)
double
UTF-8 string
boolean
'null'
an ordered list of Value
collection of name/value pairs (javascript object)

The type of the held value is represented by a ValueType and can be obtained using type().

Values of an objectValue or arrayValue can be accessed using operator[]() methods. Non-const methods will automatically create the a nullValue element if it does not exist. The sequence of an arrayValue will be automatically resized and initialized with nullValue. resize() can be used to enlarge or truncate an arrayValue.

The get() methods can be used to obtain default value in the case the required element does not exist.

It is possible to iterate over the list of member keys of an object using the getMemberNames() method.

Note: Value string-length fit in size_t, but keys must be < 2^30. (The reason is an implementation detail.) A #CharReader will raise an exception if a bound is exceeded to avoid security holes in your app, but the Value API does not check bounds. That is the responsibility of the caller.

Constructor & Destructor Documentation

◆ Value() [1/4]

Json::Value::Value ( ValueType type = nullValue )

Create a default Value of the given type.

This is a very useful constructor. To create an empty array, pass arrayValue. To create an empty object, pass objectValue. Another Value can then be set to this one by assignment. This is useful since clear() and resize() will not alter types.

Examples:

Json::Value null_value; // null
Json::Value arr_value(Json::arrayValue); // []
Json::Value obj_value(Json::objectValue); // {}

◆ Value() [2/4]

Json::Value::Value ( const char * value )

Copy til first 0. (NULL causes to seg-fault.)

◆ Value() [3/4]

Json::Value::Value	(	const char *	begin,
		const char *	end
	)

Copy all, incl zeroes.

◆ Value() [4/4]

Json::Value::Value ( const StaticString & value )

Constructs a value from a static string.

Like other value string constructor but do not duplicate the string for internal storage. The given string must remain alive after the call to this constructor.

Note: This works only for null-terminated strings. (We cannot change the size of this class, so we have nowhere to store the length, which might be computed later for various operations.)

Example of usage:

static StaticString foo("some text");

Json::Value aValue(foo);

Member Function Documentation

◆ append()

Value& Json::Value::append ( const Value & value )

Append value to array at the end.

Equivalent to jsonvalue[jsonvalue.size()] = value;

◆ as() [1/2]

template<typename T >

T Json::Value::as ( ) const

The as<T> and is<T> member function templates and specializations.

◆ as() [2/2]

template<>

float Json::Value::as ( void ) const

inline

These as specializations are type conversions, and do not have a corresponding is.

◆ asCString()

const char* Json::Value::asCString ( ) const

Embedded zeroes could cause you trouble!

◆ asString()

String Json::Value::asString ( ) const

Embedded zeroes are possible.

◆ clear()

void Json::Value::clear ( )

Remove all object members and array elements.

Precondition: type() is arrayValue, objectValue, or nullValue

Postcondition: type() is unchanged

◆ copy()

void Json::Value::copy ( const Value & other )

copy everything.

◆ copyPayload()

void Json::Value::copyPayload ( const Value & other )

copy values but leave comments and source offsets in place.

◆ demand()

Value* Json::Value::demand	(	char const *	begin,
		char const *	end
	)

Most general and efficient version of object-mutators.

Note: As stated elsewhere, behavior is undefined if (end-begin) >= 2^30

Returns: non-zero, but JSON_ASSERT if this is neither object nor nullValue.

◆ empty()

bool Json::Value::empty ( ) const

Return true if empty array, empty object, or null; otherwise, false.

◆ find()

Value const* Json::Value::find	(	char const *	begin,
		char const *	end
	)		const

Most general and efficient version of isMember()const, get()const, and operator[]const.

Note: As stated elsewhere, behavior is undefined if (end-begin) >= 2^30

◆ get() [1/4]

Value Json::Value::get	(	ArrayIndex	index,
		const Value &	defaultValue
	)		const

If the array contains at least index+1 elements, returns the element value, otherwise returns defaultValue.

◆ get() [2/4]

Value Json::Value::get	(	const char *	key,
		const Value &	defaultValue
	)		const

Return the member named key if it exist, defaultValue otherwise.

Note: deep copy

◆ get() [3/4]

Value Json::Value::get	(	const char *	begin,
		const char *	end,
		const Value &	defaultValue
	)		const

Return the member named key if it exist, defaultValue otherwise.

Note: deep copy; key may contain embedded nulls.

◆ get() [4/4]

Value Json::Value::get	(	const String &	key,
		const Value &	defaultValue
	)		const

Return the member named key if it exist, defaultValue otherwise.

Note: deep copy

Parameters

key	may contain embedded nulls.

◆ getComment()

String Json::Value::getComment ( CommentPlacement placement ) const

Include delimiters and embedded newlines.

◆ getMemberNames()

Members Json::Value::getMemberNames ( ) const

Return a list of the member names.

If null, return an empty list.

Precondition: type() is objectValue or nullValue

Postcondition: if type() was nullValue, it remains nullValue

◆ getString()

bool Json::Value::getString	(	char const **	begin,
		char const **	end
	)		const

Get raw char* of string-value.

Returns: false if !string. (Seg-fault if str or end are NULL.)

◆ insert()

bool Json::Value::insert	(	ArrayIndex	index,
		const Value &	newValue
	)

Insert value in array at specific index.

◆ isMember() [1/3]

bool Json::Value::isMember ( const char * key ) const

Return true if the object has a member named key.

Note: 'key' must be null-terminated.

◆ isMember() [2/3]

bool Json::Value::isMember ( const String & key ) const

Return true if the object has a member named key.

Parameters

key	may contain embedded nulls.

◆ isMember() [3/3]

bool Json::Value::isMember	(	const char *	begin,
		const char *	end
	)		const

Same as isMember(String const& key)const.

◆ isValidIndex()

bool Json::Value::isValidIndex ( ArrayIndex index ) const

Return true if index < size().

◆ operator bool()

Json::Value::operator bool ( ) const

explicit

Return !isNull()

◆ operator<()

bool Json::Value::operator< ( const Value & other ) const

Compare payload only, not comments etc.

◆ operator=()

Value& Json::Value::operator= ( const Value & other )

Note: Overwrite existing comments. To preserve comments, use swapPayload().

◆ operator[]() [1/9]

Value& Json::Value::operator[] ( ArrayIndex index )

Access an array element (zero based index). If the array contains less than index element, then null value are inserted in the array so that its size is index+1. (You may need to say 'value[0u]' to get your compiler to distinguish this from the operator[] which takes a string.)

◆ operator[]() [2/9]

Value& Json::Value::operator[] ( int index )

Access an array element (zero based index). If the array contains less than index element, then null value are inserted in the array so that its size is index+1. (You may need to say 'value[0u]' to get your compiler to distinguish this from the operator[] which takes a string.)

◆ operator[]() [3/9]

const Value& Json::Value::operator[] ( ArrayIndex index ) const

Access an array element (zero based index). (You may need to say 'value[0u]' to get your compiler to distinguish this from the operator[] which takes a string.)

◆ operator[]() [4/9]

const Value& Json::Value::operator[] ( int index ) const

Access an array element (zero based index). (You may need to say 'value[0u]' to get your compiler to distinguish this from the operator[] which takes a string.)

◆ operator[]() [5/9]

Value& Json::Value::operator[] ( const char * key )

Access an object value by name, create a null member if it does not exist.

Note: Because of our implementation, keys are limited to 2^30 -1 chars. Exceeding that will cause an exception.

◆ operator[]() [6/9]

const Value& Json::Value::operator[] ( const char * key ) const

Access an object value by name, returns null if there is no member with that name.

◆ operator[]() [7/9]

Value& Json::Value::operator[] ( const String & key )

Access an object value by name, create a null member if it does not exist.

Parameters

key	may contain embedded nulls.

◆ operator[]() [8/9]

const Value& Json::Value::operator[] ( const String & key ) const

Access an object value by name, returns null if there is no member with that name.

Parameters

key	may contain embedded nulls.

◆ operator[]() [9/9]

Value& Json::Value::operator[] ( const StaticString & key )

Access an object value by name, create a null member if it does not exist.

If the object has no entry for that name, then the member name used to store the new entry is not duplicated. Example of use:

Json::Value object;
static const StaticString code("code");
object[code] = 1234;

◆ removeIndex()

bool Json::Value::removeIndex	(	ArrayIndex	index,
		Value *	removed
	)

Remove the indexed array element.

O(n) expensive operations. Update 'removed' iff removed.

Returns: true if removed (no exceptions)

◆ removeMember() [1/5]

void Json::Value::removeMember ( const char * key )

Remove and return the named member.

Do nothing if it did not exist.

Precondition: type() is objectValue or nullValue

Postcondition: type() is unchanged

◆ removeMember() [2/5]

void Json::Value::removeMember ( const String & key )

Same as removeMember(const char*)

Parameters

key	may contain embedded nulls.

◆ removeMember() [3/5]

bool Json::Value::removeMember	(	const char *	key,
		Value *	removed
	)

Same as removeMember(const char* begin, const char* end, Value* removed), but 'key' is null-terminated.

◆ removeMember() [4/5]

bool Json::Value::removeMember	(	String const &	key,
		Value *	removed
	)

Remove the named map member.

Update 'removed' iff removed.

Parameters

key	may contain embedded nulls.

Returns: true iff removed (no exceptions)

◆ removeMember() [5/5]

bool Json::Value::removeMember	(	const char *	begin,
		const char *	end,
		Value *	removed
	)

Same as removeMember(String const& key, Value* removed)

◆ resize()

void Json::Value::resize ( ArrayIndex newSize )

Resize the array to newSize elements.

New elements are initialized to null. May only be called on nullValue or arrayValue.

Precondition: type() is arrayValue or nullValue

Postcondition: type() is arrayValue

◆ setComment() [1/3]

void Json::Value::setComment	(	const char *	comment,
		CommentPlacement	placement
	)

inline

Deprecated:: Always pass len.

◆ setComment() [2/3]

void Json::Value::setComment	(	const char *	comment,
		size_t	len,
		CommentPlacement	placement
	)

inline

Comments must be //... or /* ... */.

◆ setComment() [3/3]

void Json::Value::setComment	(	String	comment,
		CommentPlacement	placement
	)

Comments must be //... or /* ... */.

◆ size()

ArrayIndex Json::Value::size ( ) const

Number of values in array or object.

◆ swap()

void Json::Value::swap ( Value & other )

Swap everything.

◆ swapPayload()

void Json::Value::swapPayload ( Value & other )

Swap values but leave comments and source offsets in place.

Member Data Documentation

◆ defaultRealPrecision

constexpr UInt Json::Value::defaultRealPrecision = 17

static

Default precision for real value for string representation.

◆ maxInt

constexpr Int Json::Value::maxInt = Int(UInt(-1) / 2)

static

Maximum signed int value that can be stored in a Json::Value.

◆ maxInt64

constexpr Int64 Json::Value::maxInt64 = Int64(UInt64(-1) / 2)

static

Maximum signed 64 bits int value that can be stored in a Json::Value.

◆ maxLargestInt

constexpr LargestInt Json::Value::maxLargestInt = LargestInt(LargestUInt(-1) / 2)

static

Maximum signed integer value that can be stored in a Json::Value.

◆ maxLargestUInt

constexpr LargestUInt Json::Value::maxLargestUInt = LargestUInt(-1)

static

Maximum unsigned integer value that can be stored in a Json::Value.

◆ maxUInt

constexpr UInt Json::Value::maxUInt = UInt(-1)

static

Maximum unsigned int value that can be stored in a Json::Value.

◆ maxUInt64

constexpr UInt64 Json::Value::maxUInt64 = UInt64(-1)

static

Maximum unsigned 64 bits int value that can be stored in a Json::Value.

◆ minInt

constexpr Int Json::Value::minInt = Int(~(UInt(-1) / 2))

static

Minimum signed int value that can be stored in a Json::Value.

◆ minInt64

constexpr Int64 Json::Value::minInt64 = Int64(~(UInt64(-1) / 2))

static

Minimum signed 64 bits int value that can be stored in a Json::Value.

◆ minLargestInt

constexpr LargestInt Json::Value::minLargestInt

static

Initial value:

=

LargestInt(~(LargestUInt(-1) / 2))

Minimum signed integer value that can be stored in a Json::Value.

The documentation for this class was generated from the following file:

value.h

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Private Member Functions

Private Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

◆ Value() [1/4]

◆ Value() [2/4]

◆ Value() [3/4]

◆ Value() [4/4]

Member Function Documentation

◆ append()

◆ as() [1/2]

◆ as() [2/2]

◆ asCString()

◆ asString()

◆ clear()

◆ copy()

◆ copyPayload()

◆ demand()

◆ empty()

◆ find()

◆ get() [1/4]

◆ get() [2/4]

◆ get() [3/4]

◆ get() [4/4]

◆ getComment()

◆ getMemberNames()

◆ getString()

◆ insert()

◆ isMember() [1/3]

◆ isMember() [2/3]

◆ isMember() [3/3]

◆ isValidIndex()

◆ operator bool()

◆ operator<()

◆ operator=()

◆ operator[]() [1/9]

◆ operator[]() [2/9]

◆ operator[]() [3/9]

◆ operator[]() [4/9]

◆ operator[]() [5/9]

◆ operator[]() [6/9]

◆ operator[]() [7/9]

◆ operator[]() [8/9]

◆ operator[]() [9/9]

◆ removeIndex()

◆ removeMember() [1/5]

◆ removeMember() [2/5]

◆ removeMember() [3/5]

◆ removeMember() [4/5]

◆ removeMember() [5/5]

◆ resize()

◆ setComment() [1/3]

◆ setComment() [2/3]

◆ setComment() [3/3]

◆ size()

◆ swap()

◆ swapPayload()

Member Data Documentation

◆ defaultRealPrecision

◆ maxInt

◆ maxInt64

◆ maxLargestInt

◆ maxLargestUInt

◆ maxUInt

◆ maxUInt64

◆ minInt

◆ minInt64

◆ minLargestInt