rapidjson/include/rapidjson/document.h

#ifndef RAPIDJSON_DOCUMENT_H_
#define RAPIDJSON_DOCUMENT_H_

#include "reader.h"
#include "internal/strfunc.h"
#include <new>		// placement new

#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable : 4127) // conditional expression is constant
#endif

#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Weffc++"
#endif

#ifndef RAPIDJSON_NOMEMBERITERATORCLASS
#include "internal/meta.h"
#include <iterator> // std::iterator, std::random_access_iterator_tag
#endif

namespace rapidjson {

// Forward declaration.
template <typename Encoding, typename Allocator>
class GenericValue;

//! Name-value pair in a JSON object value.
/*!
	This class was internal to GenericValue. It used to be a inner struct.
	But a compiler (IBM XL C/C++ for AIX) have reported to have problem with that so it moved as a namespace scope struct.
	https://code.google.com/p/rapidjson/issues/detail?id=64
*/
template <typename Encoding, typename Allocator> 
struct GenericMember { 
	GenericValue<Encoding, Allocator> name;		//!< name of member (must be a string)
	GenericValue<Encoding, Allocator> value;	//!< value of member.
};

#ifndef RAPIDJSON_NOMEMBERITERATORCLASS

//! (Constant) member iterator for a JSON object value
/*!
	\tparam Const Is this a constant iterator?
	\tparam Encoding	Encoding of the value. (Even non-string values need to have the same encoding in a document)
	\tparam Allocator	Allocator type for allocating memory of object, array and string.

	This class implements a Random Access Iterator for GenericMember elements
	of a GenericValue, see ISO/IEC 14882:2003(E) C++ standard, 24.1 [lib.iterator.requirements].

	\note This iterator implementation is mainly intended to avoid implicit
		conversions from iterator values to \c NULL,
		e.g. from GenericValue::FindMember.

	\note Define \c RAPIDJSON_NOMEMBERITERATORCLASS to fall back to a
		pointer-based implementation, if your platform doesn't provide
		the C++ <iterator> header.

	\see GenericMember, GenericValue::MemberIterator, GenericValue::ConstMemberIterator
 */
template <bool Const, typename Encoding, typename Allocator>
class GenericMemberIterator
	: public std::iterator<std::random_access_iterator_tag
		, typename internal::MaybeAddConst<Const,GenericMember<Encoding,Allocator> >::Type> {

	friend class GenericValue<Encoding,Allocator>;
	template <bool, typename, typename> friend class GenericMemberIterator;

	typedef GenericMember<Encoding,Allocator> PlainType;
	typedef typename internal::MaybeAddConst<Const,PlainType>::Type ValueType;
	typedef std::iterator<std::random_access_iterator_tag,ValueType> BaseType;

public:
	//! Iterator type itself
	typedef GenericMemberIterator Type;
	//! Constant iterator type
	typedef GenericMemberIterator<true,Encoding,Allocator>  ConstType;
	//! Non-constant iterator type
	typedef GenericMemberIterator<false,Encoding,Allocator> NonConstType;

	//! Pointer to (const) GenericMember
	typedef typename BaseType::pointer         Pointer;
	//! Reference to (const) GenericMember
	typedef typename BaseType::reference       Reference;
	//! Signed integer type (e.g. \c ptrdiff_t)
	typedef typename BaseType::difference_type DifferenceType;

	//! Default constructor (singular value)
	/*! Creates an iterator pointing to no element.
		\note All operations, except for comparisons, are undefined on such values.
	 */
	GenericMemberIterator() : ptr_() {}

	//! Iterator conversions to more const
	/*!
		\param it (Non-const) iterator to copy from

		Allows the creation of an iterator from another GenericMemberIterator
		that is "less const".  Especially, creating a non-constant iterator
		from a constant iterator are disabled:
		\li const -> non-const (not ok)
		\li const -> const (ok)
		\li non-const -> const (ok)
		\li non-const -> non-const (ok)

		\note If the \c Const template parameter is already \c false, this
			constructor effectively defines a regular copy-constructor.
			Otherwise, the copy constructor is implicitly defined.
	*/
	GenericMemberIterator(const NonConstType & it) : ptr_( it.ptr_ ) {}

	//! @name stepping
	//@{
	Type& operator++(){ ++ptr_; return *this; }
	Type& operator--(){ --ptr_; return *this; }
	Type  operator++(int){ Type old(*this); ++ptr_; return old; }
	Type  operator--(int){ Type old(*this); --ptr_; return old; }
	//@}

	//! @name increment/decrement
	//@{
	Type operator+(DifferenceType n) const { return Type(ptr_+n); }
	Type operator-(DifferenceType n) const { return Type(ptr_-n); }

	Type& operator+=(DifferenceType n) { ptr_+=n; return *this; }
	Type& operator-=(DifferenceType n) { ptr_-=n; return *this; }
	//@}

	//! @name relations
	//@{
	bool operator==(Type that) const { return ptr_ == that.ptr_; }
	bool operator!=(Type that) const { return ptr_ != that.ptr_; }
	bool operator<=(Type that) const { return ptr_ <= that.ptr_; }
	bool operator>=(Type that) const { return ptr_ >= that.ptr_; }
	bool operator< (Type that) const { return ptr_ < that.ptr_; }
	bool operator> (Type that) const { return ptr_ > that.ptr_; }
	//@}

	//! @name dereference
	//@{
	Reference operator*() const { return *ptr_; }
	Pointer   operator->() const { return ptr_; }
	Reference operator[](DifferenceType n) const { return ptr_[n]; }
	//@}

	//! Distance
	DifferenceType operator-(Type that) const { return ptr_-that.ptr_; }

private:
	//! Internal constructor from plain pointer
	explicit GenericMemberIterator(Pointer p) : ptr_(p) {}

	Pointer ptr_; //!< raw pointer
};

#else // RAPIDJSON_NOMEMBERITERATORCLASS

// class-based member iterator implementation disabled, use plain pointers

template <bool Const, typename Encoding, typename Allocator>
struct GenericMemberIterator;

//! non-const GenericMemberIterator
template <typename Encoding, typename Allocator>
struct GenericMemberIterator<false,Encoding,Allocator> {
	//! use plain pointer as iterator type
	typedef GenericMember<Encoding,Allocator>* Type;
};
//! const GenericMemberIterator
template <typename Encoding, typename Allocator>
struct GenericMemberIterator<true,Encoding,Allocator> {
	//! use plain const pointer as iterator type
	typedef const GenericMember<Encoding,Allocator>* Type;
};

#endif // RAPIDJSON_NOMEMBERITERATORCLASS

///////////////////////////////////////////////////////////////////////////////
// GenericValue

//! Represents a JSON value. Use Value for UTF8 encoding and default allocator.
/*!
	A JSON value can be one of 7 types. This class is a variant type supporting
	these types.

	Use the Value if UTF8 and default allocator

	\tparam Encoding	Encoding of the value. (Even non-string values need to have the same encoding in a document)
	\tparam Allocator	Allocator type for allocating memory of object, array and string.
*/
#pragma pack (push, 4)
template <typename Encoding, typename Allocator = MemoryPoolAllocator<> > 
class GenericValue {
public:
	//! Name-value pair in an object.
	typedef GenericMember<Encoding, Allocator> Member;
	typedef Encoding EncodingType;					//!< Encoding type from template parameter.
	typedef Allocator AllocatorType;				//!< Allocator type from template parameter.
	typedef typename Encoding::Ch Ch;				//!< Character type derived from Encoding.
	typedef typename GenericMemberIterator<false,Encoding,Allocator>::Type MemberIterator;	//!< Member iterator for iterating in object.
	typedef typename GenericMemberIterator<true,Encoding,Allocator>::Type ConstMemberIterator;	//!< Constant member iterator for iterating in object.
	typedef GenericValue* ValueIterator;			//!< Value iterator for iterating in array.
	typedef const GenericValue* ConstValueIterator;	//!< Constant value iterator for iterating in array.

	//!@name Constructors and destructor.
	//@{

	//! Default constructor creates a null value.
	GenericValue() : data_(), flags_(kNullFlag) {}

	//! Copy constructor is not permitted.
private:
	GenericValue(const GenericValue& rhs);

public:

	//! Constructor with JSON value type.
	/*! This creates a Value of specified type with default content.
		\param type	Type of the value.
		\note Default content for number is zero.
	*/
	GenericValue(Type type) : data_(), flags_() {
		static const unsigned defaultFlags[7] = {
			kNullFlag, kFalseFlag, kTrueFlag, kObjectFlag, kArrayFlag, kConstStringFlag,
			kNumberAnyFlag
		};
		RAPIDJSON_ASSERT(type <= kNumberType);
		flags_ = defaultFlags[type];
	}

	//! Explicit copy constructor (with allocator)
	/*! Creates a copy of a Value by using the given Allocator
		\tparam SourceAllocator allocator of \c rhs
		\param rhs Value to copy from (read-only)
		\param allocator Allocator to use for copying
		\see CopyFrom()
	*/
	template< typename SourceAllocator >
	GenericValue(const GenericValue<Encoding,SourceAllocator>& rhs, Allocator & allocator);

	//! Constructor for boolean value.
	explicit GenericValue(bool b) : data_(), flags_(b ? kTrueFlag : kFalseFlag) {}

	//! Constructor for int value.
	explicit GenericValue(int i) : data_(), flags_(kNumberIntFlag) {
		data_.n.i64 = i;
		if (i >= 0)
			flags_ |= kUintFlag | kUint64Flag;
	}

	//! Constructor for unsigned value.
	explicit GenericValue(unsigned u) : data_(), flags_(kNumberUintFlag) {
		data_.n.u64 = u; 
		if (!(u & 0x80000000))
			flags_ |= kIntFlag | kInt64Flag;
	}

	//! Constructor for int64_t value.
	explicit GenericValue(int64_t i64) : data_(), flags_(kNumberInt64Flag) {
		data_.n.i64 = i64;
		if (i64 >= 0) {
			flags_ |= kNumberUint64Flag;
			if (!(static_cast<uint64_t>(i64) & UINT64_C(0xFFFFFFFF00000000)))
				flags_ |= kUintFlag;
			if (!(static_cast<uint64_t>(i64) & UINT64_C(0xFFFFFFFF80000000)))
				flags_ |= kIntFlag;
		}
		else if (i64 >= INT64_C(-2147483648))
			flags_ |= kIntFlag;
	}

	//! Constructor for uint64_t value.
	explicit GenericValue(uint64_t u64) : data_(), flags_(kNumberUint64Flag) {
		data_.n.u64 = u64;
		if (!(u64 & UINT64_C(0x8000000000000000)))
			flags_ |= kInt64Flag;
		if (!(u64 & UINT64_C(0xFFFFFFFF00000000)))
			flags_ |= kUintFlag;
		if (!(u64 & UINT64_C(0xFFFFFFFF80000000)))
			flags_ |= kIntFlag;
	}

	//! Constructor for double value.
	explicit GenericValue(double d) : data_(), flags_(kNumberDoubleFlag) { data_.n.d = d; }

	//! Constructor for constant string (i.e. do not make a copy of string)
	GenericValue(const Ch* s, SizeType length) : data_(), flags_() { 
		RAPIDJSON_ASSERT(s != NULL);
		flags_ = kConstStringFlag;
		data_.s.str = s;
		data_.s.length = length;
	}

	//! Constructor for constant string (i.e. do not make a copy of string)
	explicit GenericValue(const Ch* s) : data_(), flags_() { SetStringRaw(s, internal::StrLen(s)); }

	//! Constructor for copy-string (i.e. do make a copy of string)
	GenericValue(const Ch* s, SizeType length, Allocator& allocator) : data_(), flags_() { SetStringRaw(s, length, allocator); }

	//! Constructor for copy-string (i.e. do make a copy of string)
	GenericValue(const Ch*s, Allocator& allocator) : data_(), flags_() { SetStringRaw(s, internal::StrLen(s), allocator); }

	//! Destructor.
	/*! Need to destruct elements of array, members of object, or copy-string.
	*/
	~GenericValue() {
		if (Allocator::kNeedFree) {	// Shortcut by Allocator's trait
			switch(flags_) {
			case kArrayFlag:
				for (GenericValue* v = data_.a.elements; v != data_.a.elements + data_.a.size; ++v)
					v->~GenericValue();
				Allocator::Free(data_.a.elements);
				break;

			case kObjectFlag:
				for (MemberIterator m = MemberBegin(); m != MemberEnd(); ++m) {
					m->name.~GenericValue();
					m->value.~GenericValue();
				}
				Allocator::Free(data_.o.members);
				break;

			case kCopyStringFlag:
				Allocator::Free(const_cast<Ch*>(data_.s.str));
				break;
			}
		}
	}

	//@}

	//!@name Assignment operators
	//@{

	//! Assignment with move semantics.
	/*! \param rhs Source of the assignment. It will become a null value after assignment.
	*/
	GenericValue& operator=(GenericValue& rhs) {
		RAPIDJSON_ASSERT(this != &rhs);
		this->~GenericValue();
		RawAssign(rhs);
		return *this;
	}

	//! Assignment with primitive types.
	/*! \tparam T Either Type, int, unsigned, int64_t, uint64_t, const Ch*
		\param value The value to be assigned.
	*/
	template <typename T>
	GenericValue& operator=(T value) {
		this->~GenericValue();
		new (this) GenericValue(value);
		return *this;
	}

	//! Deep-copy assignment from Value
	/*! Assigns a \b copy of the Value to the current Value object
		\tparam SourceAllocator Allocator type of \c rhs
		\param rhs Value to copy from (read-only)
		\param allocator Allocator to use for copying
	 */
	template <typename SourceAllocator>
	GenericValue& CopyFrom(const GenericValue<Encoding,SourceAllocator>& rhs, Allocator& allocator) {
		RAPIDJSON_ASSERT((void*)this != (void const*)&rhs);
		this->~GenericValue();
		new (this) GenericValue(rhs,allocator);
		return *this;
	}

	GenericValue& Swap(GenericValue& other) {
		char temp[sizeof(GenericValue)];
		memcpy(&temp[0], this, sizeof(GenericValue));
		memcpy(this, &other, sizeof(GenericValue));
		memcpy(&other, temp, sizeof(GenericValue));
		return *this;
	}

	//@}

	//!@name Type
	//@{

	Type GetType()	const { return static_cast<Type>(flags_ & kTypeMask); }
	bool IsNull()	const { return flags_ == kNullFlag; }
	bool IsFalse()	const { return flags_ == kFalseFlag; }
	bool IsTrue()	const { return flags_ == kTrueFlag; }
	bool IsBool()	const { return (flags_ & kBoolFlag) != 0; }
	bool IsObject()	const { return flags_ == kObjectFlag; }
	bool IsArray()	const { return flags_ == kArrayFlag; }
	bool IsNumber() const { return (flags_ & kNumberFlag) != 0; }
	bool IsInt()	const { return (flags_ & kIntFlag) != 0; }
	bool IsUint()	const { return (flags_ & kUintFlag) != 0; }
	bool IsInt64()	const { return (flags_ & kInt64Flag) != 0; }
	bool IsUint64()	const { return (flags_ & kUint64Flag) != 0; }
	bool IsDouble() const { return (flags_ & kDoubleFlag) != 0; }
	bool IsString() const { return (flags_ & kStringFlag) != 0; }

	//@}

	//!@name Null
	//@{

	GenericValue& SetNull() { this->~GenericValue(); new (this) GenericValue(); return *this; }

	//@}

	//!@name Bool
	//@{

	bool GetBool() const { RAPIDJSON_ASSERT(IsBool()); return flags_ == kTrueFlag; }
	GenericValue& SetBool(bool b) { this->~GenericValue(); new (this) GenericValue(b); return *this; }

	//@}

	//!@name Object
	//@{

	//! Set this value as an empty object.
	GenericValue& SetObject() { this->~GenericValue(); new (this) GenericValue(kObjectType); return *this; }

	//! Get the value associated with the name.
	/*!
		\note In version 0.1x, if the member is not found, this function returns a null value. This makes issue 7.
		Since 0.2, if the name is not correct, it will assert.
		If user is unsure whether a member exists, user should use HasMember() first.
		A better approach is to use the now public FindMember().
	*/
	GenericValue& operator[](const Ch* name) {
		MemberIterator member = FindMember(name);
		if (member != MemberEnd())
			return member->value;
		else {
			RAPIDJSON_ASSERT(false);	// see above note
			static GenericValue NullValue;
			return NullValue;
		}
	}
	const GenericValue& operator[](const Ch* name) const { return const_cast<GenericValue&>(*this)[name]; }

	// This version is faster because it does not need a StrLen(). 
	// It can also handle string with null character.
	GenericValue& operator[](const GenericValue& name) {
		MemberIterator member = FindMember(name);
		if (member != MemberEnd())
			return member->value;
		else {
			RAPIDJSON_ASSERT(false);	// see above note
			static GenericValue NullValue;
			return NullValue;
		}
	}
	const GenericValue& operator[](const GenericValue& name) const { return const_cast<GenericValue&>(*this)[name]; }

	//! Const member iterator
	/*! \pre IsObject() == true */
	ConstMemberIterator MemberBegin() const	{ RAPIDJSON_ASSERT(IsObject()); return ConstMemberIterator(data_.o.members); }
	//! Const \em past-the-end member iterator
	/*! \pre IsObject() == true */
	ConstMemberIterator MemberEnd()	const	{ RAPIDJSON_ASSERT(IsObject()); return ConstMemberIterator(data_.o.members + data_.o.size); }
	//! Member iterator
	/*! \pre IsObject() == true */
	MemberIterator MemberBegin()			{ RAPIDJSON_ASSERT(IsObject()); return MemberIterator(data_.o.members); }
	//! \em Past-the-end member iterator
	/*! \pre IsObject() == true */
	MemberIterator MemberEnd()				{ RAPIDJSON_ASSERT(IsObject()); return MemberIterator(data_.o.members + data_.o.size); }

	//! Check whether a member exists in the object.
	/*!
		\note It is better to use FindMember() directly if you need the obtain the value as well.
	*/
	bool HasMember(const Ch* name) const { return FindMember(name) != MemberEnd(); }

	// This version is faster because it does not need a StrLen(). 
	// It can also handle string with null character.
	bool HasMember(const GenericValue& name) const { return FindMember(name) != MemberEnd(); }

	//! Find member by name.
	/*!
		\pre IsObject() == true
		\return Iterator to member, if it exists.
			Otherwise returns \ref MemberEnd().

		\note Earlier versions of Rapidjson returned a \c NULL pointer, in case
			the requested member doesn't exist. For consistency with e.g.
			\c std::map, this has been changed to MemberEnd() now.
	*/
	MemberIterator FindMember(const Ch* name) {
		RAPIDJSON_ASSERT(name);
		RAPIDJSON_ASSERT(IsObject());

		SizeType len = internal::StrLen(name);
		MemberIterator member = MemberBegin();
		for (; member != MemberEnd(); ++member)
			if (member->name.data_.s.length == len && memcmp(member->name.data_.s.str, name, len * sizeof(Ch)) == 0)
				break;
		return member;
	}

	ConstMemberIterator FindMember(const Ch* name) const { return const_cast<GenericValue&>(*this).FindMember(name); }

	// This version is faster because it does not need a StrLen(). 
	// It can also handle string with null character.
	MemberIterator FindMember(const GenericValue& name) {
		RAPIDJSON_ASSERT(IsObject());
		RAPIDJSON_ASSERT(name.IsString());
		SizeType len = name.data_.s.length;
		MemberIterator member = MemberBegin();
		for ( ; member != MemberEnd(); ++member)
			if (member->name.data_.s.length == len && memcmp(member->name.data_.s.str, name.data_.s.str, len * sizeof(Ch)) == 0)
				break;
		return member;
	}
	ConstMemberIterator FindMember(const GenericValue& name) const { return const_cast<GenericValue&>(*this).FindMember(name); }

	//! Add a member (name-value pair) to the object.
	/*! \param name A string value as name of member.
		\param value Value of any type.
	    \param allocator Allocator for reallocating memory.
	    \return The value itself for fluent API.
	    \note The ownership of name and value will be transfered to this object if success.
	*/
	GenericValue& AddMember(GenericValue& name, GenericValue& value, Allocator& allocator) {
		RAPIDJSON_ASSERT(IsObject());
		RAPIDJSON_ASSERT(name.IsString());

		Object& o = data_.o;
		if (o.size >= o.capacity) {
			if (o.capacity == 0) {
				o.capacity = kDefaultObjectCapacity;
				o.members = (Member*)allocator.Malloc(o.capacity * sizeof(Member));
			}
			else {
				SizeType oldCapacity = o.capacity;
				o.capacity *= 2;
				o.members = (Member*)allocator.Realloc(o.members, oldCapacity * sizeof(Member), o.capacity * sizeof(Member));
			}
		}
		o.members[o.size].name.RawAssign(name);
		o.members[o.size].value.RawAssign(value);
		o.size++;
		return *this;
	}

	GenericValue& AddMember(const Ch* name, Allocator& nameAllocator, GenericValue& value, Allocator& allocator) {
		GenericValue n(name, internal::StrLen(name), nameAllocator);
		return AddMember(n, value, allocator);
	}

	GenericValue& AddMember(const Ch* name, GenericValue& value, Allocator& allocator) {
		GenericValue n(name, internal::StrLen(name));
		return AddMember(n, value, allocator);
	}

	template <typename T>
	GenericValue& AddMember(const Ch* name, T value, Allocator& allocator) {
		GenericValue n(name, internal::StrLen(name));
		GenericValue v(value);
		return AddMember(n, v, allocator);
	}

	//! Remove a member in object by its name.
	/*! \param name Name of member to be removed.
	    \return Whether the member existed.
	    \note Removing member is implemented by moving the last member. So the ordering of members is changed.
	*/
	bool RemoveMember(const Ch* name) {
		MemberIterator m = FindMember(name);
		if (m != MemberEnd()) {
			RemoveMember(m);
			return true;
		}
		else
			return false;
	}

	bool RemoveMember(const GenericValue& name) {
		MemberIterator m = FindMember(name);
		if (m != MemberEnd()) {
			RemoveMember(m);
			return true;
		}
		else
			return false;
	}

	//! Remove a member in object by iterator.
	/*! \param m member iterator (obtained by FindMember() or MemberBegin()).
		\return the new iterator after removal.
		\note Removing member is implemented by moving the last member. So the ordering of members is changed.
	*/
	MemberIterator RemoveMember(MemberIterator m) {
		RAPIDJSON_ASSERT(IsObject());
		RAPIDJSON_ASSERT(data_.o.size > 0);
		RAPIDJSON_ASSERT(data_.o.members != 0);
		RAPIDJSON_ASSERT(m >= MemberBegin() && m < MemberEnd());

		MemberIterator last(data_.o.members + (data_.o.size - 1));
		if (data_.o.size > 1 && m != last) {
			// Move the last one to this place
			m->name = last->name;
			m->value = last->value;
		}
		else {
			// Only one left, just destroy
			m->name.~GenericValue();
			m->value.~GenericValue();
		}
		--data_.o.size;
		return m;
	}

	//@}

	//!@name Array
	//@{

	//! Set this value as an empty array.
	GenericValue& SetArray() {	this->~GenericValue(); new (this) GenericValue(kArrayType); return *this; }

	//! Get the number of elements in array.
	SizeType Size() const { RAPIDJSON_ASSERT(IsArray()); return data_.a.size; }

	//! Get the capacity of array.
	SizeType Capacity() const { RAPIDJSON_ASSERT(IsArray()); return data_.a.capacity; }

	//! Check whether the array is empty.
	bool Empty() const { RAPIDJSON_ASSERT(IsArray()); return data_.a.size == 0; }

	//! Remove all elements in the array.
	/*! This function do not deallocate memory in the array, i.e. the capacity is unchanged.
	*/
	void Clear() {
		RAPIDJSON_ASSERT(IsArray()); 
		for (SizeType i = 0; i < data_.a.size; ++i)
			data_.a.elements[i].~GenericValue();
		data_.a.size = 0;
	}

	//! Get an element from array by index.
	/*! \param index Zero-based index of element.
\code
Value a(kArrayType);
a.PushBack(123);
int x = a[0].GetInt();				// Error: operator[ is ambiguous, as 0 also mean a null pointer of const char* type.
int y = a[SizeType(0)].GetInt();	// Cast to SizeType will work.
int z = a[0u].GetInt();				// This works too.
\endcode
	*/
	GenericValue& operator[](SizeType index) {
		RAPIDJSON_ASSERT(IsArray());
		RAPIDJSON_ASSERT(index < data_.a.size);
		return data_.a.elements[index];
	}
	const GenericValue& operator[](SizeType index) const { return const_cast<GenericValue&>(*this)[index]; }

	//! Element iterator
	ValueIterator Begin() { RAPIDJSON_ASSERT(IsArray()); return data_.a.elements; }
	ValueIterator End() { RAPIDJSON_ASSERT(IsArray()); return data_.a.elements + data_.a.size; }
	ConstValueIterator Begin() const { return const_cast<GenericValue&>(*this).Begin(); }
	ConstValueIterator End() const { return const_cast<GenericValue&>(*this).End(); }

	//! Request the array to have enough capacity to store elements.
	/*! \param newCapacity	The capacity that the array at least need to have.
		\param allocator	The allocator for allocating memory. It must be the same one use previously.
		\return The value itself for fluent API.
	*/
	GenericValue& Reserve(SizeType newCapacity, Allocator &allocator) {
		RAPIDJSON_ASSERT(IsArray());
		if (newCapacity > data_.a.capacity) {
			data_.a.elements = (GenericValue*)allocator.Realloc(data_.a.elements, data_.a.capacity * sizeof(GenericValue), newCapacity * sizeof(GenericValue));
			data_.a.capacity = newCapacity;
		}
		return *this;
	}

	//! Append a value at the end of the array.
	/*! \param value		The value to be appended.
	    \param allocator	The allocator for allocating memory. It must be the same one use previously.
	    \return The value itself for fluent API.
	    \note The ownership of the value will be transfered to this object if success.
	    \note If the number of elements to be appended is known, calls Reserve() once first may be more efficient.
	*/
	GenericValue& PushBack(GenericValue& value, Allocator& allocator) {
		RAPIDJSON_ASSERT(IsArray());
		if (data_.a.size >= data_.a.capacity)
			Reserve(data_.a.capacity == 0 ? kDefaultArrayCapacity : data_.a.capacity * 2, allocator);
		data_.a.elements[data_.a.size++].RawAssign(value);
		return *this;
	}

	template <typename T>
	GenericValue& PushBack(T value, Allocator& allocator) {
		GenericValue v(value);
		return PushBack(v, allocator);
	}

	//! Remove the last element in the array.
	GenericValue& PopBack() {
		RAPIDJSON_ASSERT(IsArray());
		RAPIDJSON_ASSERT(!Empty());
		data_.a.elements[--data_.a.size].~GenericValue();
		return *this;
	}
	//@}

	//!@name Number
	//@{

	int GetInt() const			{ RAPIDJSON_ASSERT(flags_ & kIntFlag);   return data_.n.i.i;   }
	unsigned GetUint() const	{ RAPIDJSON_ASSERT(flags_ & kUintFlag);  return data_.n.u.u;   }
	int64_t GetInt64() const	{ RAPIDJSON_ASSERT(flags_ & kInt64Flag); return data_.n.i64; }
	uint64_t GetUint64() const	{ RAPIDJSON_ASSERT(flags_ & kUint64Flag); return data_.n.u64; }

	double GetDouble() const {
		RAPIDJSON_ASSERT(IsNumber());
		if ((flags_ & kDoubleFlag) != 0)				return data_.n.d;	// exact type, no conversion.
		if ((flags_ & kIntFlag) != 0)					return data_.n.i.i;	// int -> double
		if ((flags_ & kUintFlag) != 0)					return data_.n.u.u;	// unsigned -> double
		if ((flags_ & kInt64Flag) != 0)					return (double)data_.n.i64; // int64_t -> double (may lose precision)
		RAPIDJSON_ASSERT((flags_ & kUint64Flag) != 0);	return (double)data_.n.u64;	// uint64_t -> double (may lose precision)
	}

	GenericValue& SetInt(int i)				{ this->~GenericValue(); new (this) GenericValue(i);	return *this; }
	GenericValue& SetUint(unsigned u)		{ this->~GenericValue(); new (this) GenericValue(u);	return *this; }
	GenericValue& SetInt64(int64_t i64)		{ this->~GenericValue(); new (this) GenericValue(i64);	return *this; }
	GenericValue& SetUint64(uint64_t u64)	{ this->~GenericValue(); new (this) GenericValue(u64);	return *this; }
	GenericValue& SetDouble(double d)		{ this->~GenericValue(); new (this) GenericValue(d);	return *this; }

	//@}

	//!@name String
	//@{

	const Ch* GetString() const { RAPIDJSON_ASSERT(IsString()); return data_.s.str; }

	//! Get the length of string.
	/*! Since rapidjson permits "\\u0000" in the json string, strlen(v.GetString()) may not equal to v.GetStringLength().
	*/
	SizeType GetStringLength() const { RAPIDJSON_ASSERT(IsString()); return data_.s.length; }

	//! Set this value as a string without copying source string.
	/*! This version has better performance with supplied length, and also support string containing null character.
		\param s source string pointer. 
		\param length The length of source string, excluding the trailing null terminator.
		\return The value itself for fluent API.
	*/
	GenericValue& SetString(const Ch* s, SizeType length) { this->~GenericValue(); SetStringRaw(s, length); return *this; }

	//! Set this value as a string without copying source string.
	/*! \param s source string pointer. 
		\return The value itself for fluent API.
	*/
	GenericValue& SetString(const Ch* s) { return SetString(s, internal::StrLen(s)); }

	//! Set this value as a string by copying from source string.
	/*! This version has better performance with supplied length, and also support string containing null character.
		\param s source string. 
		\param length The length of source string, excluding the trailing null terminator.
		\param allocator Allocator for allocating copied buffer. Commonly use document.GetAllocator().
		\return The value itself for fluent API.
	*/
	GenericValue& SetString(const Ch* s, SizeType length, Allocator& allocator) { this->~GenericValue(); SetStringRaw(s, length, allocator); return *this; }

	//! Set this value as a string by copying from source string.
	/*!	\param s source string. 
		\param allocator Allocator for allocating copied buffer. Commonly use document.GetAllocator().
		\return The value itself for fluent API.
	*/
	GenericValue& SetString(const Ch* s, Allocator& allocator) {	SetString(s, internal::StrLen(s), allocator); return *this; }

	//@}

	//! Generate events of this value to a Handler.
	/*! This function adopts the GoF visitor pattern.
		Typical usage is to output this JSON value as JSON text via Writer, which is a Handler.
		It can also be used to deep clone this value via GenericDocument, which is also a Handler.
		\tparam Handler type of handler.
		\param handler An object implementing concept Handler.
	*/
	template <typename Handler>
	const GenericValue& Accept(Handler& handler) const {
		switch(GetType()) {
		case kNullType:		handler.Null(); break;
		case kFalseType:	handler.Bool(false); break;
		case kTrueType:		handler.Bool(true); break;

		case kObjectType:
			handler.StartObject();
			for (ConstMemberIterator m = MemberBegin(); m != MemberEnd(); ++m) {
				handler.String(m->name.data_.s.str, m->name.data_.s.length, (m->name.flags_ & kCopyFlag) != 0);
				m->value.Accept(handler);
			}
			handler.EndObject(data_.o.size);
			break;

		case kArrayType:
			handler.StartArray();
			for (GenericValue* v = data_.a.elements; v != data_.a.elements + data_.a.size; ++v)
				v->Accept(handler);
			handler.EndArray(data_.a.size);
			break;

		case kStringType:
			handler.String(data_.s.str, data_.s.length, (flags_ & kCopyFlag) != 0);
			break;

		case kNumberType:
			if (IsInt())			handler.Int(data_.n.i.i);
			else if (IsUint())		handler.Uint(data_.n.u.u);
			else if (IsInt64())		handler.Int64(data_.n.i64);
			else if (IsUint64())	handler.Uint64(data_.n.u64);
			else					handler.Double(data_.n.d);
			break;
		}
		return *this;
	}

private:
	template <typename, typename>
	friend class GenericDocument;

	enum {
		kBoolFlag = 0x100,
		kNumberFlag = 0x200,
		kIntFlag = 0x400,
		kUintFlag = 0x800,
		kInt64Flag = 0x1000,
		kUint64Flag = 0x2000,
		kDoubleFlag = 0x4000,
		kStringFlag = 0x100000,
		kCopyFlag = 0x200000,

		// Initial flags of different types.
		kNullFlag = kNullType,
		kTrueFlag = kTrueType | kBoolFlag,
		kFalseFlag = kFalseType | kBoolFlag,
		kNumberIntFlag = kNumberType | kNumberFlag | kIntFlag | kInt64Flag,
		kNumberUintFlag = kNumberType | kNumberFlag | kUintFlag | kUint64Flag | kInt64Flag,
		kNumberInt64Flag = kNumberType | kNumberFlag | kInt64Flag,
		kNumberUint64Flag = kNumberType | kNumberFlag | kUint64Flag,
		kNumberDoubleFlag = kNumberType | kNumberFlag | kDoubleFlag,
		kNumberAnyFlag = kNumberType | kNumberFlag | kIntFlag | kInt64Flag | kUintFlag | kUint64Flag | kDoubleFlag,
		kConstStringFlag = kStringType | kStringFlag,
		kCopyStringFlag = kStringType | kStringFlag | kCopyFlag,
		kObjectFlag = kObjectType,
		kArrayFlag = kArrayType,

		kTypeMask = 0xFF	// bitwise-and with mask of 0xFF can be optimized by compiler
	};

	static const SizeType kDefaultArrayCapacity = 16;
	static const SizeType kDefaultObjectCapacity = 16;

	struct String {
		const Ch* str;
		SizeType length;
		unsigned hashcode;	//!< reserved
	};	// 12 bytes in 32-bit mode, 16 bytes in 64-bit mode

	// By using proper binary layout, retrieval of different integer types do not need conversions.
	union Number {
#if RAPIDJSON_ENDIAN == RAPIDJSON_LITTLEENDIAN
		struct I {
			int i;
			char padding[4];
		}i;
		struct U {
			unsigned u;
			char padding2[4];
		}u;
#else
		struct I {
			char padding[4];
			int i;
		}i;
		struct U {
			char padding2[4];
			unsigned u;
		}u;
#endif
		int64_t i64;
		uint64_t u64;
		double d;
	};	// 8 bytes

	struct Object {
		Member* members;
		SizeType size;
		SizeType capacity;
	};	// 12 bytes in 32-bit mode, 16 bytes in 64-bit mode

	struct Array {
		GenericValue<Encoding, Allocator>* elements;
		SizeType size;
		SizeType capacity;
	};	// 12 bytes in 32-bit mode, 16 bytes in 64-bit mode

	union Data {
		String s;
		Number n;
		Object o;
		Array a;
	};	// 12 bytes in 32-bit mode, 16 bytes in 64-bit mode

	// Initialize this value as array with initial data, without calling destructor.
	void SetArrayRaw(GenericValue* values, SizeType count, Allocator& allocator) {
		flags_ = kArrayFlag;
		data_.a.elements = (GenericValue*)allocator.Malloc(count * sizeof(GenericValue));
		memcpy(data_.a.elements, values, count * sizeof(GenericValue));
		data_.a.size = data_.a.capacity = count;
	}

	//! Initialize this value as object with initial data, without calling destructor.
	void SetObjectRaw(Member* members, SizeType count, Allocator& allocator) {
		flags_ = kObjectFlag;
		data_.o.members = (Member*)allocator.Malloc(count * sizeof(Member));
		memcpy(data_.o.members, members, count * sizeof(Member));
		data_.o.size = data_.o.capacity = count;
	}

	//! Initialize this value as constant string, without calling destructor.
	void SetStringRaw(const Ch* s, SizeType length) {
		RAPIDJSON_ASSERT(s != NULL);
		flags_ = kConstStringFlag;
		data_.s.str = s;
		data_.s.length = length;
	}

	//! Initialize this value as copy string with initial data, without calling destructor.
	void SetStringRaw(const Ch* s, SizeType length, Allocator& allocator) {
		RAPIDJSON_ASSERT(s != NULL);
		flags_ = kCopyStringFlag;
		data_.s.str = (Ch *)allocator.Malloc((length + 1) * sizeof(Ch));
		data_.s.length = length;
		memcpy(const_cast<Ch*>(data_.s.str), s, length * sizeof(Ch));
		const_cast<Ch*>(data_.s.str)[length] = '\0';
	}

	//! Assignment without calling destructor
	void RawAssign(GenericValue& rhs) {
		data_ = rhs.data_;
		flags_ = rhs.flags_;
		rhs.flags_ = kNullFlag;
	}

	Data data_;
	unsigned flags_;
};
#pragma pack (pop)

//! Value with UTF8 encoding.
typedef GenericValue<UTF8<> > Value;

///////////////////////////////////////////////////////////////////////////////
// GenericDocument 

//! A document for parsing JSON text as DOM.
/*!
	\note implements Handler concept
	\tparam Encoding encoding for both parsing and string storage.
	\tparam Allocator allocator for allocating memory for the DOM, and the stack during parsing.
*/
template <typename Encoding, typename Allocator = MemoryPoolAllocator<> >
class GenericDocument : public GenericValue<Encoding, Allocator> {
public:
	typedef typename Encoding::Ch Ch;						//!< Character type derived from Encoding.
	typedef GenericValue<Encoding, Allocator> ValueType;	//!< Value type of the document.
	typedef Allocator AllocatorType;						//!< Allocator type from template parameter.

	//! Constructor
	/*! \param allocator		Optional allocator for allocating stack memory.
		\param stackCapacity	Initial capacity of stack in bytes.
	*/
	GenericDocument(Allocator* allocator = 0, size_t stackCapacity = kDefaultStackCapacity) : stack_(allocator, stackCapacity), parseErrorCode_(kParseErrorNone), errorOffset_(0) {}

	//! Parse JSON text from an input stream.
	/*! \tparam parseFlags Combination of ParseFlag.
		\param is Input stream to be parsed.
		\return The document itself for fluent API.
	*/
	template <unsigned parseFlags, typename SourceEncoding, typename InputStream>
	GenericDocument& ParseStream(InputStream& is) {
		ValueType::SetNull(); // Remove existing root if exist
		GenericReader<SourceEncoding, Encoding, Allocator> reader(&GetAllocator());
		if (reader.template Parse<parseFlags>(is, *this)) {
			RAPIDJSON_ASSERT(stack_.GetSize() == sizeof(ValueType)); // Got one and only one root object
			this->RawAssign(*stack_.template Pop<ValueType>(1));	// Add this-> to prevent issue 13.
			parseErrorCode_ = kParseErrorNone;
			errorOffset_ = 0;
		}
		else {
			parseErrorCode_ = reader.GetParseErrorCode();
			errorOffset_ = reader.GetErrorOffset();
			ClearStack();
		}
		return *this;
	}

	template <unsigned parseFlags, typename InputStream>
	GenericDocument& ParseStream(InputStream& is) {
		return ParseStream<parseFlags,Encoding,InputStream>(is);
	}

	template <typename InputStream>
	GenericDocument& ParseStream(InputStream& is) {
		return ParseStream<kParseDefaultFlags, Encoding, InputStream>(is);
	}

	//! Parse JSON text from a mutable string.
	/*! \tparam parseFlags Combination of ParseFlag.
		\param str Mutable zero-terminated string to be parsed.
		\return The document itself for fluent API.
	*/
	template <unsigned parseFlags, typename SourceEncoding>
	GenericDocument& ParseInsitu(Ch* str) {
		GenericInsituStringStream<Encoding> s(str);
		return ParseStream<parseFlags | kParseInsituFlag, SourceEncoding>(s);
	}

	template <unsigned parseFlags>
	GenericDocument& ParseInsitu(Ch* str) {
		return ParseInsitu<parseFlags, Encoding>(str);
	}

	GenericDocument& ParseInsitu(Ch* str) {
		return ParseInsitu<kParseDefaultFlags, Encoding>(str);
	}

	//! Parse JSON text from a read-only string.
	/*! \tparam parseFlags Combination of ParseFlag (must not contain kParseInsituFlag).
		\param str Read-only zero-terminated string to be parsed.
	*/
	template <unsigned parseFlags, typename SourceEncoding>
	GenericDocument& Parse(const Ch* str) {
		RAPIDJSON_ASSERT(!(parseFlags & kParseInsituFlag));
		GenericStringStream<SourceEncoding> s(str);
		return ParseStream<parseFlags, SourceEncoding>(s);
	}

	template <unsigned parseFlags>
	GenericDocument& Parse(const Ch* str) {
		return Parse<parseFlags, Encoding>(str);
	}

	GenericDocument& Parse(const Ch* str) {
		return Parse<kParseDefaultFlags>(str);
	}

	//! Whether a parse error was occured in the last parsing.
	bool HasParseError() const { return parseErrorCode_ != kParseErrorNone; }

	//! Get the message of parsing error.
	ParseErrorCode GetParseError() const { return parseErrorCode_; }

	//! Get the offset in character of the parsing error.
	size_t GetErrorOffset() const { return errorOffset_; }

	//! Get the allocator of this document.
	Allocator& GetAllocator() {	return stack_.GetAllocator(); }

	//! Get the capacity of stack in bytes.
	size_t GetStackCapacity() const { return stack_.GetCapacity(); }

private:
	// callers of the following private Handler functions
	template <typename,typename,typename> friend class GenericReader; // for parsing
	friend class GenericValue<Encoding,Allocator>; // for deep copying

	// Implementation of Handler
	void Null()	{ new (stack_.template Push<ValueType>()) ValueType(); }
	void Bool(bool b) { new (stack_.template Push<ValueType>()) ValueType(b); }
	void Int(int i) { new (stack_.template Push<ValueType>()) ValueType(i); }
	void Uint(unsigned i) { new (stack_.template Push<ValueType>()) ValueType(i); }
	void Int64(int64_t i) { new (stack_.template Push<ValueType>()) ValueType(i); }
	void Uint64(uint64_t i) { new (stack_.template Push<ValueType>()) ValueType(i); }
	void Double(double d) { new (stack_.template Push<ValueType>()) ValueType(d); }

	void String(const Ch* str, SizeType length, bool copy) { 
		if (copy) 
			new (stack_.template Push<ValueType>()) ValueType(str, length, GetAllocator());
		else
			new (stack_.template Push<ValueType>()) ValueType(str, length);
	}

	void StartObject() { new (stack_.template Push<ValueType>()) ValueType(kObjectType); }
	
	void EndObject(SizeType memberCount) {
		typename ValueType::Member* members = stack_.template Pop<typename ValueType::Member>(memberCount);
		stack_.template Top<ValueType>()->SetObjectRaw(members, (SizeType)memberCount, GetAllocator());
	}

	void StartArray() { new (stack_.template Push<ValueType>()) ValueType(kArrayType); }
	
	void EndArray(SizeType elementCount) {
		ValueType* elements = stack_.template Pop<ValueType>(elementCount);
		stack_.template Top<ValueType>()->SetArrayRaw(elements, elementCount, GetAllocator());
	}

private:
	// Prohibit assignment
	GenericDocument& operator=(const GenericDocument&);

	void ClearStack() {
		if (Allocator::kNeedFree)
			while (stack_.GetSize() > 0)	// Here assumes all elements in stack array are GenericValue (Member is actually 2 GenericValue objects)
				(stack_.template Pop<ValueType>(1))->~ValueType();
		else
			stack_.Clear();
	}

	static const size_t kDefaultStackCapacity = 1024;
	internal::Stack<Allocator> stack_;
	ParseErrorCode parseErrorCode_;
	size_t errorOffset_;
};

typedef GenericDocument<UTF8<> > Document;

// defined here due to the dependency on GenericDocument
template <typename Encoding, typename Allocator>
template <typename SourceAllocator>
inline
GenericValue<Encoding,Allocator>::GenericValue(const GenericValue<Encoding,SourceAllocator>& rhs, Allocator& allocator)
{
	GenericDocument<Encoding,Allocator> d(&allocator);
	rhs.Accept(d);
	RawAssign(*d.stack_.template Pop<GenericValue>(1));
}

} // namespace rapidjson

#ifdef _MSC_VER
#pragma warning(pop)
#endif

#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif

#endif // RAPIDJSON_DOCUMENT_H_