1 // Tencent is pleased to support the open source community by making RapidJSON available.
2 //
3 // Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved.
4 //
5 // Licensed under the MIT License (the "License"); you may not use this file except
6 // in compliance with the License. You may obtain a copy of the License at
7 //
8 // http://opensource.org/licenses/MIT
9 //
10 // Unless required by applicable law or agreed to in writing, software distributed
11 // under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
12 // CONDITIONS OF ANY KIND, either express or implied. See the License for the
13 // specific language governing permissions and limitations under the License.
14 
15 #ifndef RAPIDJSON_DOCUMENT_H_
16 #define RAPIDJSON_DOCUMENT_H_
17 
18 /*! \file document.h */
19 
20 #include "reader.h"
21 #include "internal/meta.h"
22 #include "internal/strfunc.h"
23 #include <new>      // placement new
24 
25 #ifdef _MSC_VER
26 RAPIDJSON_DIAG_PUSH
27 RAPIDJSON_DIAG_OFF(4127) // conditional expression is constant
28 #elif defined(__GNUC__)
29 RAPIDJSON_DIAG_PUSH
30 RAPIDJSON_DIAG_OFF(effc++)
31 #endif
32 
33 ///////////////////////////////////////////////////////////////////////////////
34 // RAPIDJSON_HAS_STDSTRING
35 
36 #ifndef RAPIDJSON_HAS_STDSTRING
37 #ifdef RAPIDJSON_DOXYGEN_RUNNING
38 #define RAPIDJSON_HAS_STDSTRING 1 // force generation of documentation
39 #else
40 #define RAPIDJSON_HAS_STDSTRING 0 // no std::string support by default
41 #endif
42 /*! \def RAPIDJSON_HAS_STDSTRING
43     \ingroup RAPIDJSON_CONFIG
44     \brief Enable RapidJSON support for \c std::string
45 
46     By defining this preprocessor symbol to \c 1, several convenience functions for using
47     \ref rapidjson::GenericValue with \c std::string are enabled, especially
48     for construction and comparison.
49 
50     \hideinitializer
51 */
52 #endif // !defined(RAPIDJSON_HAS_STDSTRING)
53 
54 #if RAPIDJSON_HAS_STDSTRING
55 #include <string>
56 #endif // RAPIDJSON_HAS_STDSTRING
57 
58 #ifndef RAPIDJSON_NOMEMBERITERATORCLASS
59 #include <iterator> // std::iterator, std::random_access_iterator_tag
60 #endif
61 
62 #if RAPIDJSON_HAS_CXX11_RVALUE_REFS
63 #include <utility> // std::move
64 #endif
65 
66 RAPIDJSON_NAMESPACE_BEGIN
67 
68 // Forward declaration.
69 template <typename Encoding, typename Allocator>
70 class GenericValue;
71 
72 template <typename Encoding, typename Allocator, typename StackAllocator>
73 class GenericDocument;
74 
75 //! Name-value pair in a JSON object value.
76 /*!
77     This class was internal to GenericValue. It used to be a inner struct.
78     But a compiler (IBM XL C/C++ for AIX) have reported to have problem with that so it moved as a namespace scope struct.
79     https://code.google.com/p/rapidjson/issues/detail?id=64
80 */
81 template <typename Encoding, typename Allocator>
82 struct GenericMember {
83     GenericValue<Encoding, Allocator> name;     //!< name of member (must be a string)
84     GenericValue<Encoding, Allocator> value;    //!< value of member.
85 };
86 
87 ///////////////////////////////////////////////////////////////////////////////
88 // GenericMemberIterator
89 
90 #ifndef RAPIDJSON_NOMEMBERITERATORCLASS
91 
92 //! (Constant) member iterator for a JSON object value
93 /*!
94     \tparam Const Is this a constant iterator?
95     \tparam Encoding    Encoding of the value. (Even non-string values need to have the same encoding in a document)
96     \tparam Allocator   Allocator type for allocating memory of object, array and string.
97 
98     This class implements a Random Access Iterator for GenericMember elements
99     of a GenericValue, see ISO/IEC 14882:2003(E) C++ standard, 24.1 [lib.iterator.requirements].
100 
101     \note This iterator implementation is mainly intended to avoid implicit
102         conversions from iterator values to \c NULL,
103         e.g. from GenericValue::FindMember.
104 
105     \note Define \c RAPIDJSON_NOMEMBERITERATORCLASS to fall back to a
106         pointer-based implementation, if your platform doesn't provide
107         the C++ <iterator> header.
108 
109     \see GenericMember, GenericValue::MemberIterator, GenericValue::ConstMemberIterator
110  */
111 template <bool Const, typename Encoding, typename Allocator>
112 class GenericMemberIterator
113     : public std::iterator<std::random_access_iterator_tag
114         , typename internal::MaybeAddConst<Const,GenericMember<Encoding,Allocator> >::Type> {
115 
116     friend class GenericValue<Encoding,Allocator>;
117     template <bool, typename, typename> friend class GenericMemberIterator;
118 
119     typedef GenericMember<Encoding,Allocator> PlainType;
120     typedef typename internal::MaybeAddConst<Const,PlainType>::Type ValueType;
121     typedef std::iterator<std::random_access_iterator_tag,ValueType> BaseType;
122 
123 public:
124     //! Iterator type itself
125     typedef GenericMemberIterator Iterator;
126     //! Constant iterator type
127     typedef GenericMemberIterator<true,Encoding,Allocator>  ConstIterator;
128     //! Non-constant iterator type
129     typedef GenericMemberIterator<false,Encoding,Allocator> NonConstIterator;
130 
131     //! Pointer to (const) GenericMember
132     typedef typename BaseType::pointer         Pointer;
133     //! Reference to (const) GenericMember
134     typedef typename BaseType::reference       Reference;
135     //! Signed integer type (e.g. \c ptrdiff_t)
136     typedef typename BaseType::difference_type DifferenceType;
137 
138     //! Default constructor (singular value)
139     /*! Creates an iterator pointing to no element.
140         \note All operations, except for comparisons, are undefined on such values.
141      */
GenericMemberIterator()142     GenericMemberIterator() : ptr_() {}
143 
144     //! Iterator conversions to more const
145     /*!
146         \param it (Non-const) iterator to copy from
147 
148         Allows the creation of an iterator from another GenericMemberIterator
149         that is "less const".  Especially, creating a non-constant iterator
150         from a constant iterator are disabled:
151         \li const -> non-const (not ok)
152         \li const -> const (ok)
153         \li non-const -> const (ok)
154         \li non-const -> non-const (ok)
155 
156         \note If the \c Const template parameter is already \c false, this
157             constructor effectively defines a regular copy-constructor.
158             Otherwise, the copy constructor is implicitly defined.
159     */
GenericMemberIterator(const NonConstIterator & it)160     GenericMemberIterator(const NonConstIterator & it) : ptr_(it.ptr_) {}
161 
162     //! @name stepping
163     //@{
164     Iterator& operator++(){ ++ptr_; return *this; }
165     Iterator& operator--(){ --ptr_; return *this; }
166     Iterator  operator++(int){ Iterator old(*this); ++ptr_; return old; }
167     Iterator  operator--(int){ Iterator old(*this); --ptr_; return old; }
168     //@}
169 
170     //! @name increment/decrement
171     //@{
172     Iterator operator+(DifferenceType n) const { return Iterator(ptr_+n); }
173     Iterator operator-(DifferenceType n) const { return Iterator(ptr_-n); }
174 
175     Iterator& operator+=(DifferenceType n) { ptr_+=n; return *this; }
176     Iterator& operator-=(DifferenceType n) { ptr_-=n; return *this; }
177     //@}
178 
179     //! @name relations
180     //@{
181     bool operator==(ConstIterator that) const { return ptr_ == that.ptr_; }
182     bool operator!=(ConstIterator that) const { return ptr_ != that.ptr_; }
183     bool operator<=(ConstIterator that) const { return ptr_ <= that.ptr_; }
184     bool operator>=(ConstIterator that) const { return ptr_ >= that.ptr_; }
185     bool operator< (ConstIterator that) const { return ptr_ < that.ptr_; }
186     bool operator> (ConstIterator that) const { return ptr_ > that.ptr_; }
187     //@}
188 
189     //! @name dereference
190     //@{
191     Reference operator*() const { return *ptr_; }
192     Pointer   operator->() const { return ptr_; }
193     Reference operator[](DifferenceType n) const { return ptr_[n]; }
194     //@}
195 
196     //! Distance
197     DifferenceType operator-(ConstIterator that) const { return ptr_-that.ptr_; }
198 
199 private:
200     //! Internal constructor from plain pointer
GenericMemberIterator(Pointer p)201     explicit GenericMemberIterator(Pointer p) : ptr_(p) {}
202 
203     Pointer ptr_; //!< raw pointer
204 };
205 
206 #else // RAPIDJSON_NOMEMBERITERATORCLASS
207 
208 // class-based member iterator implementation disabled, use plain pointers
209 
210 template <bool Const, typename Encoding, typename Allocator>
211 struct GenericMemberIterator;
212 
213 //! non-const GenericMemberIterator
214 template <typename Encoding, typename Allocator>
215 struct GenericMemberIterator<false,Encoding,Allocator> {
216     //! use plain pointer as iterator type
217     typedef GenericMember<Encoding,Allocator>* Iterator;
218 };
219 //! const GenericMemberIterator
220 template <typename Encoding, typename Allocator>
221 struct GenericMemberIterator<true,Encoding,Allocator> {
222     //! use plain const pointer as iterator type
223     typedef const GenericMember<Encoding,Allocator>* Iterator;
224 };
225 
226 #endif // RAPIDJSON_NOMEMBERITERATORCLASS
227 
228 ///////////////////////////////////////////////////////////////////////////////
229 // GenericStringRef
230 
231 //! Reference to a constant string (not taking a copy)
232 /*!
233     \tparam CharType character type of the string
234 
235     This helper class is used to automatically infer constant string
236     references for string literals, especially from \c const \b (!)
237     character arrays.
238 
239     The main use is for creating JSON string values without copying the
240     source string via an \ref Allocator.  This requires that the referenced
241     string pointers have a sufficient lifetime, which exceeds the lifetime
242     of the associated GenericValue.
243 
244     \b Example
245     \code
246     Value v("foo");   // ok, no need to copy & calculate length
247     const char foo[] = "foo";
248     v.SetString(foo); // ok
249 
250     const char* bar = foo;
251     // Value x(bar); // not ok, can't rely on bar's lifetime
252     Value x(StringRef(bar)); // lifetime explicitly guaranteed by user
253     Value y(StringRef(bar, 3));  // ok, explicitly pass length
254     \endcode
255 
256     \see StringRef, GenericValue::SetString
257 */
258 template<typename CharType>
259 struct GenericStringRef {
260     typedef CharType Ch; //!< character type of the string
261 
262     //! Create string reference from \c const character array
263     /*!
264         This constructor implicitly creates a constant string reference from
265         a \c const character array.  It has better performance than
266         \ref StringRef(const CharType*) by inferring the string \ref length
267         from the array length, and also supports strings containing null
268         characters.
269 
270         \tparam N length of the string, automatically inferred
271 
272         \param str Constant character array, lifetime assumed to be longer
273             than the use of the string in e.g. a GenericValue
274 
275         \post \ref s == str
276 
277         \note Constant complexity.
278         \note There is a hidden, private overload to disallow references to
279             non-const character arrays to be created via this constructor.
280             By this, e.g. function-scope arrays used to be filled via
281             \c snprintf are excluded from consideration.
282             In such cases, the referenced string should be \b copied to the
283             GenericValue instead.
284      */
285     template<SizeType N>
286     GenericStringRef(const CharType (&str)[N]) RAPIDJSON_NOEXCEPT
287         : s(str), length(N-1) {}
288 
289     //! Explicitly create string reference from \c const character pointer
290     /*!
291         This constructor can be used to \b explicitly  create a reference to
292         a constant string pointer.
293 
294         \see StringRef(const CharType*)
295 
296         \param str Constant character pointer, lifetime assumed to be longer
297             than the use of the string in e.g. a GenericValue
298 
299         \post \ref s == str
300 
301         \note There is a hidden, private overload to disallow references to
302             non-const character arrays to be created via this constructor.
303             By this, e.g. function-scope arrays used to be filled via
304             \c snprintf are excluded from consideration.
305             In such cases, the referenced string should be \b copied to the
306             GenericValue instead.
307      */
308     explicit GenericStringRef(const CharType* str)
309         : s(str), length(internal::StrLen(str)){ RAPIDJSON_ASSERT(s != NULL); }
310 
311     //! Create constant string reference from pointer and length
312     /*! \param str constant string, lifetime assumed to be longer than the use of the string in e.g. a GenericValue
313         \param len length of the string, excluding the trailing NULL terminator
314 
315         \post \ref s == str && \ref length == len
316         \note Constant complexity.
317      */
318     GenericStringRef(const CharType* str, SizeType len)
319         : s(str), length(len) { RAPIDJSON_ASSERT(s != NULL); }
320 
321     //! implicit conversion to plain CharType pointer
322     operator const Ch *() const { return s; }
323 
324     const Ch* const s; //!< plain CharType pointer
325     const SizeType length; //!< length of the string (excluding the trailing NULL terminator)
326 
327 private:
328     //! Disallow copy-assignment
329     GenericStringRef operator=(const GenericStringRef&);
330     //! Disallow construction from non-const array
331     template<SizeType N>
332     GenericStringRef(CharType (&str)[N]) /* = delete */;
333 };
334 
335 //! Mark a character pointer as constant string
336 /*! Mark a plain character pointer as a "string literal".  This function
337     can be used to avoid copying a character string to be referenced as a
338     value in a JSON GenericValue object, if the string's lifetime is known
339     to be valid long enough.
340     \tparam CharType Character type of the string
341     \param str Constant string, lifetime assumed to be longer than the use of the string in e.g. a GenericValue
342     \return GenericStringRef string reference object
343     \relatesalso GenericStringRef
344 
345     \see GenericValue::GenericValue(StringRefType), GenericValue::operator=(StringRefType), GenericValue::SetString(StringRefType), GenericValue::PushBack(StringRefType, Allocator&), GenericValue::AddMember
346 */
347 template<typename CharType>
348 inline GenericStringRef<CharType> StringRef(const CharType* str) {
349     return GenericStringRef<CharType>(str, internal::StrLen(str));
350 }
351 
352 //! Mark a character pointer as constant string
353 /*! Mark a plain character pointer as a "string literal".  This function
354     can be used to avoid copying a character string to be referenced as a
355     value in a JSON GenericValue object, if the string's lifetime is known
356     to be valid long enough.
357 
358     This version has better performance with supplied length, and also
359     supports string containing null characters.
360 
361     \tparam CharType character type of the string
362     \param str Constant string, lifetime assumed to be longer than the use of the string in e.g. a GenericValue
363     \param length The length of source string.
364     \return GenericStringRef string reference object
365     \relatesalso GenericStringRef
366 */
367 template<typename CharType>
368 inline GenericStringRef<CharType> StringRef(const CharType* str, size_t length) {
369     return GenericStringRef<CharType>(str, SizeType(length));
370 }
371 
372 #if RAPIDJSON_HAS_STDSTRING
373 //! Mark a string object as constant string
374 /*! Mark a string object (e.g. \c std::string) as a "string literal".
375     This function can be used to avoid copying a string to be referenced as a
376     value in a JSON GenericValue object, if the string's lifetime is known
377     to be valid long enough.
378 
379     \tparam CharType character type of the string
380     \param str Constant string, lifetime assumed to be longer than the use of the string in e.g. a GenericValue
381     \return GenericStringRef string reference object
382     \relatesalso GenericStringRef
383     \note Requires the definition of the preprocessor symbol \ref RAPIDJSON_HAS_STDSTRING.
384 */
385 template<typename CharType>
386 inline GenericStringRef<CharType> StringRef(const std::basic_string<CharType>& str) {
387     return GenericStringRef<CharType>(str.data(), SizeType(str.size()));
388 }
389 #endif
390 
391 ///////////////////////////////////////////////////////////////////////////////
392 // GenericValue type traits
393 namespace internal {
394 
395 template <typename T, typename Encoding = void, typename Allocator = void>
396 struct IsGenericValueImpl : FalseType {};
397 
398 // select candidates according to nested encoding and allocator types
399 template <typename T> struct IsGenericValueImpl<T, typename Void<typename T::EncodingType>::Type, typename Void<typename T::AllocatorType>::Type>
400     : IsBaseOf<GenericValue<typename T::EncodingType, typename T::AllocatorType>, T>::Type {};
401 
402 // helper to match arbitrary GenericValue instantiations, including derived classes
403 template <typename T> struct IsGenericValue : IsGenericValueImpl<T>::Type {};
404 
405 } // namespace internal
406 
407 ///////////////////////////////////////////////////////////////////////////////
408 // GenericValue
409 
410 //! Represents a JSON value. Use Value for UTF8 encoding and default allocator.
411 /*!
412     A JSON value can be one of 7 types. This class is a variant type supporting
413     these types.
414 
415     Use the Value if UTF8 and default allocator
416 
417     \tparam Encoding    Encoding of the value. (Even non-string values need to have the same encoding in a document)
418     \tparam Allocator   Allocator type for allocating memory of object, array and string.
419 */
420 template <typename Encoding, typename Allocator = MemoryPoolAllocator<> >
421 class GenericValue {
422 public:
423     //! Name-value pair in an object.
424     typedef GenericMember<Encoding, Allocator> Member;
425     typedef Encoding EncodingType;                  //!< Encoding type from template parameter.
426     typedef Allocator AllocatorType;                //!< Allocator type from template parameter.
427     typedef typename Encoding::Ch Ch;               //!< Character type derived from Encoding.
428     typedef GenericStringRef<Ch> StringRefType;     //!< Reference to a constant string
429     typedef typename GenericMemberIterator<false,Encoding,Allocator>::Iterator MemberIterator;  //!< Member iterator for iterating in object.
430     typedef typename GenericMemberIterator<true,Encoding,Allocator>::Iterator ConstMemberIterator;  //!< Constant member iterator for iterating in object.
431     typedef GenericValue* ValueIterator;            //!< Value iterator for iterating in array.
432     typedef const GenericValue* ConstValueIterator; //!< Constant value iterator for iterating in array.
433     typedef GenericValue<Encoding, Allocator> ValueType;    //!< Value type of itself.
434 
435     //!@name Constructors and destructor.
436     //@{
437 
438     //! Default constructor creates a null value.
439     GenericValue() RAPIDJSON_NOEXCEPT : data_(), flags_(kNullFlag) {}
440 
441 #if RAPIDJSON_HAS_CXX11_RVALUE_REFS
442     //! Move constructor in C++11
443     GenericValue(GenericValue&& rhs) RAPIDJSON_NOEXCEPT : data_(rhs.data_), flags_(rhs.flags_) {
444         rhs.flags_ = kNullFlag; // give up contents
445     }
446 #endif
447 
448 private:
449     //! Copy constructor is not permitted.
450     GenericValue(const GenericValue& rhs);
451 
452 #if RAPIDJSON_HAS_CXX11_RVALUE_REFS
453     //! Moving from a GenericDocument is not permitted.
454     template <typename StackAllocator>
455     GenericValue(GenericDocument<Encoding,Allocator,StackAllocator>&& rhs);
456 
457     //! Move assignment from a GenericDocument is not permitted.
458     template <typename StackAllocator>
459     GenericValue& operator=(GenericDocument<Encoding,Allocator,StackAllocator>&& rhs);
460 #endif
461 
462 public:
463 
464     //! Constructor with JSON value type.
465     /*! This creates a Value of specified type with default content.
466         \param type Type of the value.
467         \note Default content for number is zero.
468     */
469     explicit GenericValue(Type type) RAPIDJSON_NOEXCEPT : data_(), flags_() {
470         static const unsigned defaultFlags[7] = {
471             kNullFlag, kFalseFlag, kTrueFlag, kObjectFlag, kArrayFlag, kShortStringFlag,
472             kNumberAnyFlag
473         };
474         RAPIDJSON_ASSERT(type <= kNumberType);
475         flags_ = defaultFlags[type];
476 
477         // Use ShortString to store empty string.
478         if (type == kStringType)
479             data_.ss.SetLength(0);
480     }
481 
482     //! Explicit copy constructor (with allocator)
483     /*! Creates a copy of a Value by using the given Allocator
484         \tparam SourceAllocator allocator of \c rhs
485         \param rhs Value to copy from (read-only)
486         \param allocator Allocator for allocating copied elements and buffers. Commonly use GenericDocument::GetAllocator().
487         \see CopyFrom()
488     */
489     template< typename SourceAllocator >
490     GenericValue(const GenericValue<Encoding, SourceAllocator>& rhs, Allocator & allocator);
491 
492     //! Constructor for boolean value.
493     /*! \param b Boolean value
494         \note This constructor is limited to \em real boolean values and rejects
495             implicitly converted types like arbitrary pointers.  Use an explicit cast
496             to \c bool, if you want to construct a boolean JSON value in such cases.
497      */
498 #ifndef RAPIDJSON_DOXYGEN_RUNNING // hide SFINAE from Doxygen
499     template <typename T>
500     explicit GenericValue(T b, RAPIDJSON_ENABLEIF((internal::IsSame<T,bool>))) RAPIDJSON_NOEXCEPT
501 #else
502     explicit GenericValue(bool b) RAPIDJSON_NOEXCEPT
503 #endif
504         : data_(), flags_(b ? kTrueFlag : kFalseFlag) {
505             // safe-guard against failing SFINAE
506             RAPIDJSON_STATIC_ASSERT((internal::IsSame<bool,T>::Value));
507     }
508 
509     //! Constructor for int value.
510     explicit GenericValue(int i) RAPIDJSON_NOEXCEPT : data_(), flags_(kNumberIntFlag) {
511         data_.n.i64 = i;
512         if (i >= 0)
513             flags_ |= kUintFlag | kUint64Flag;
514     }
515 
516     //! Constructor for unsigned value.
517     explicit GenericValue(unsigned u) RAPIDJSON_NOEXCEPT : data_(), flags_(kNumberUintFlag) {
518         data_.n.u64 = u;
519         if (!(u & 0x80000000))
520             flags_ |= kIntFlag | kInt64Flag;
521     }
522 
523     //! Constructor for int64_t value.
524     explicit GenericValue(int64_t i64) RAPIDJSON_NOEXCEPT : data_(), flags_(kNumberInt64Flag) {
525         data_.n.i64 = i64;
526         if (i64 >= 0) {
527             flags_ |= kNumberUint64Flag;
528             if (!(static_cast<uint64_t>(i64) & RAPIDJSON_UINT64_C2(0xFFFFFFFF, 0x00000000)))
529                 flags_ |= kUintFlag;
530             if (!(static_cast<uint64_t>(i64) & RAPIDJSON_UINT64_C2(0xFFFFFFFF, 0x80000000)))
531                 flags_ |= kIntFlag;
532         }
533         else if (i64 >= static_cast<int64_t>(RAPIDJSON_UINT64_C2(0xFFFFFFFF, 0x80000000)))
534             flags_ |= kIntFlag;
535     }
536 
537     //! Constructor for uint64_t value.
538     explicit GenericValue(uint64_t u64) RAPIDJSON_NOEXCEPT : data_(), flags_(kNumberUint64Flag) {
539         data_.n.u64 = u64;
540         if (!(u64 & RAPIDJSON_UINT64_C2(0x80000000, 0x00000000)))
541             flags_ |= kInt64Flag;
542         if (!(u64 & RAPIDJSON_UINT64_C2(0xFFFFFFFF, 0x00000000)))
543             flags_ |= kUintFlag;
544         if (!(u64 & RAPIDJSON_UINT64_C2(0xFFFFFFFF, 0x80000000)))
545             flags_ |= kIntFlag;
546     }
547 
548     //! Constructor for double value.
549     explicit GenericValue(double d) RAPIDJSON_NOEXCEPT : data_(), flags_(kNumberDoubleFlag) { data_.n.d = d; }
550 
551     //! Constructor for constant string (i.e. do not make a copy of string)
552     GenericValue(const Ch* s, SizeType length) RAPIDJSON_NOEXCEPT : data_(), flags_() { SetStringRaw(StringRef(s, length)); }
553 
554     //! Constructor for constant string (i.e. do not make a copy of string)
555     explicit GenericValue(StringRefType s) RAPIDJSON_NOEXCEPT : data_(), flags_() { SetStringRaw(s); }
556 
557     //! Constructor for copy-string (i.e. do make a copy of string)
558     GenericValue(const Ch* s, SizeType length, Allocator& allocator) : data_(), flags_() { SetStringRaw(StringRef(s, length), allocator); }
559 
560     //! Constructor for copy-string (i.e. do make a copy of string)
561     GenericValue(const Ch*s, Allocator& allocator) : data_(), flags_() { SetStringRaw(StringRef(s), allocator); }
562 
563 #if RAPIDJSON_HAS_STDSTRING
564     //! Constructor for copy-string from a string object (i.e. do make a copy of string)
565     /*! \note Requires the definition of the preprocessor symbol \ref RAPIDJSON_HAS_STDSTRING.
566      */
567     GenericValue(const std::basic_string<Ch>& s, Allocator& allocator) : data_(), flags_() { SetStringRaw(StringRef(s), allocator); }
568 #endif
569 
570     //! Destructor.
571     /*! Need to destruct elements of array, members of object, or copy-string.
572     */
573     ~GenericValue() {
574         if (Allocator::kNeedFree) { // Shortcut by Allocator's trait
575             switch(flags_) {
576             case kArrayFlag:
577                 for (GenericValue* v = data_.a.elements; v != data_.a.elements + data_.a.size; ++v)
578                     v->~GenericValue();
579                 Allocator::Free(data_.a.elements);
580                 break;
581 
582             case kObjectFlag:
583                 for (MemberIterator m = MemberBegin(); m != MemberEnd(); ++m)
584                     m->~Member();
585                 Allocator::Free(data_.o.members);
586                 break;
587 
588             case kCopyStringFlag:
589                 Allocator::Free(const_cast<Ch*>(data_.s.str));
590                 break;
591 
592             default:
593                 break;  // Do nothing for other types.
594             }
595         }
596     }
597 
598     //@}
599 
600     //!@name Assignment operators
601     //@{
602 
603     //! Assignment with move semantics.
604     /*! \param rhs Source of the assignment. It will become a null value after assignment.
605     */
606     GenericValue& operator=(GenericValue& rhs) RAPIDJSON_NOEXCEPT {
607         RAPIDJSON_ASSERT(this != &rhs);
608         this->~GenericValue();
609         RawAssign(rhs);
610         return *this;
611     }
612 
613 #if RAPIDJSON_HAS_CXX11_RVALUE_REFS
614     //! Move assignment in C++11
615     GenericValue& operator=(GenericValue&& rhs) RAPIDJSON_NOEXCEPT {
616         return *this = rhs.Move();
617     }
618 #endif
619 
620     //! Assignment of constant string reference (no copy)
621     /*! \param str Constant string reference to be assigned
622         \note This overload is needed to avoid clashes with the generic primitive type assignment overload below.
623         \see GenericStringRef, operator=(T)
624     */
625     GenericValue& operator=(StringRefType str) RAPIDJSON_NOEXCEPT {
626         GenericValue s(str);
627         return *this = s;
628     }
629 
630     //! Assignment with primitive types.
631     /*! \tparam T Either \ref Type, \c int, \c unsigned, \c int64_t, \c uint64_t
632         \param value The value to be assigned.
633 
634         \note The source type \c T explicitly disallows all pointer types,
635             especially (\c const) \ref Ch*.  This helps avoiding implicitly
636             referencing character strings with insufficient lifetime, use
637             \ref SetString(const Ch*, Allocator&) (for copying) or
638             \ref StringRef() (to explicitly mark the pointer as constant) instead.
639             All other pointer types would implicitly convert to \c bool,
640             use \ref SetBool() instead.
641     */
642     template <typename T>
643     RAPIDJSON_DISABLEIF_RETURN((internal::IsPointer<T>), (GenericValue&))
644     operator=(T value) {
645         GenericValue v(value);
646         return *this = v;
647     }
648 
649     //! Deep-copy assignment from Value
650     /*! Assigns a \b copy of the Value to the current Value object
651         \tparam SourceAllocator Allocator type of \c rhs
652         \param rhs Value to copy from (read-only)
653         \param allocator Allocator to use for copying
654      */
655     template <typename SourceAllocator>
656     GenericValue& CopyFrom(const GenericValue<Encoding, SourceAllocator>& rhs, Allocator& allocator) {
657         RAPIDJSON_ASSERT((void*)this != (void const*)&rhs);
658         this->~GenericValue();
659         new (this) GenericValue(rhs, allocator);
660         return *this;
661     }
662 
663     //! Exchange the contents of this value with those of other.
664     /*!
665         \param other Another value.
666         \note Constant complexity.
667     */
668     GenericValue& Swap(GenericValue& other) RAPIDJSON_NOEXCEPT {
669         GenericValue temp;
670         temp.RawAssign(*this);
671         RawAssign(other);
672         other.RawAssign(temp);
673         return *this;
674     }
675 
676     //! free-standing swap function helper
677     /*!
678         Helper function to enable support for common swap implementation pattern based on \c std::swap:
679         \code
680         void swap(MyClass& a, MyClass& b) {
681             using std::swap;
682             swap(a.value, b.value);
683             // ...
684         }
685         \endcode
686         \see Swap()
687      */
688     friend inline void swap(GenericValue& a, GenericValue& b) RAPIDJSON_NOEXCEPT { a.Swap(b); }
689 
690     //! Prepare Value for move semantics
691     /*! \return *this */
692     GenericValue& Move() RAPIDJSON_NOEXCEPT { return *this; }
693     //@}
694 
695     //!@name Equal-to and not-equal-to operators
696     //@{
697     //! Equal-to operator
698     /*!
699         \note If an object contains duplicated named member, comparing equality with any object is always \c false.
700         \note Linear time complexity (number of all values in the subtree and total lengths of all strings).
701     */
702     template <typename SourceAllocator>
703     bool operator==(const GenericValue<Encoding, SourceAllocator>& rhs) const {
704         typedef GenericValue<Encoding, SourceAllocator> RhsType;
705         if (GetType() != rhs.GetType())
706             return false;
707 
708         switch (GetType()) {
709         case kObjectType: // Warning: O(n^2) inner-loop
710             if (data_.o.size != rhs.data_.o.size)
711                 return false;
712             for (ConstMemberIterator lhsMemberItr = MemberBegin(); lhsMemberItr != MemberEnd(); ++lhsMemberItr) {
713                 typename RhsType::ConstMemberIterator rhsMemberItr = rhs.FindMember(lhsMemberItr->name);
714                 if (rhsMemberItr == rhs.MemberEnd() || lhsMemberItr->value != rhsMemberItr->value)
715                     return false;
716             }
717             return true;
718 
719         case kArrayType:
720             if (data_.a.size != rhs.data_.a.size)
721                 return false;
722             for (SizeType i = 0; i < data_.a.size; i++)
723                 if ((*this)[i] != rhs[i])
724                     return false;
725             return true;
726 
727         case kStringType:
728             return StringEqual(rhs);
729 
730         case kNumberType:
731             if (IsDouble() || rhs.IsDouble()) {
732                 double a = GetDouble();     // May convert from integer to double.
733                 double b = rhs.GetDouble(); // Ditto
734                 return a >= b && a <= b;    // Prevent -Wfloat-equal
735             }
736             else
737                 return data_.n.u64 == rhs.data_.n.u64;
738 
739         default: // kTrueType, kFalseType, kNullType
740             return true;
741         }
742     }
743 
744     //! Equal-to operator with const C-string pointer
745     bool operator==(const Ch* rhs) const { return *this == GenericValue(StringRef(rhs)); }
746 
747 #if RAPIDJSON_HAS_STDSTRING
748     //! Equal-to operator with string object
749     /*! \note Requires the definition of the preprocessor symbol \ref RAPIDJSON_HAS_STDSTRING.
750      */
751     bool operator==(const std::basic_string<Ch>& rhs) const { return *this == GenericValue(StringRef(rhs)); }
752 #endif
753 
754     //! Equal-to operator with primitive types
755     /*! \tparam T Either \ref Type, \c int, \c unsigned, \c int64_t, \c uint64_t, \c double, \c true, \c false
756     */
757     template <typename T> RAPIDJSON_DISABLEIF_RETURN((internal::OrExpr<internal::IsPointer<T>,internal::IsGenericValue<T> >), (bool)) operator==(const T& rhs) const { return *this == GenericValue(rhs); }
758 
759     //! Not-equal-to operator
760     /*! \return !(*this == rhs)
761      */
762     template <typename SourceAllocator>
763     bool operator!=(const GenericValue<Encoding, SourceAllocator>& rhs) const { return !(*this == rhs); }
764 
765     //! Not-equal-to operator with const C-string pointer
766     bool operator!=(const Ch* rhs) const { return !(*this == rhs); }
767 
768     //! Not-equal-to operator with arbitrary types
769     /*! \return !(*this == rhs)
770      */
771     template <typename T> RAPIDJSON_DISABLEIF_RETURN((internal::IsGenericValue<T>), (bool)) operator!=(const T& rhs) const { return !(*this == rhs); }
772 
773     //! Equal-to operator with arbitrary types (symmetric version)
774     /*! \return (rhs == lhs)
775      */
776     template <typename T> friend RAPIDJSON_DISABLEIF_RETURN((internal::IsGenericValue<T>), (bool)) operator==(const T& lhs, const GenericValue& rhs) { return rhs == lhs; }
777 
778     //! Not-Equal-to operator with arbitrary types (symmetric version)
779     /*! \return !(rhs == lhs)
780      */
781     template <typename T> friend RAPIDJSON_DISABLEIF_RETURN((internal::IsGenericValue<T>), (bool)) operator!=(const T& lhs, const GenericValue& rhs) { return !(rhs == lhs); }
782     //@}
783 
784     //!@name Type
785     //@{
786 
787     Type GetType()  const { return static_cast<Type>(flags_ & kTypeMask); }
788     bool IsNull()   const { return flags_ == kNullFlag; }
789     bool IsFalse()  const { return flags_ == kFalseFlag; }
790     bool IsTrue()   const { return flags_ == kTrueFlag; }
791     bool IsBool()   const { return (flags_ & kBoolFlag) != 0; }
792     bool IsObject() const { return flags_ == kObjectFlag; }
793     bool IsArray()  const { return flags_ == kArrayFlag; }
794     bool IsNumber() const { return (flags_ & kNumberFlag) != 0; }
795     bool IsInt()    const { return (flags_ & kIntFlag) != 0; }
796     bool IsUint()   const { return (flags_ & kUintFlag) != 0; }
797     bool IsInt64()  const { return (flags_ & kInt64Flag) != 0; }
798     bool IsUint64() const { return (flags_ & kUint64Flag) != 0; }
799     bool IsDouble() const { return (flags_ & kDoubleFlag) != 0; }
800     bool IsString() const { return (flags_ & kStringFlag) != 0; }
801 
802     //@}
803 
804     //!@name Null
805     //@{
806 
807     GenericValue& SetNull() { this->~GenericValue(); new (this) GenericValue(); return *this; }
808 
809     //@}
810 
811     //!@name Bool
812     //@{
813 
814     bool GetBool() const { RAPIDJSON_ASSERT(IsBool()); return flags_ == kTrueFlag; }
815     //!< Set boolean value
816     /*! \post IsBool() == true */
817     GenericValue& SetBool(bool b) { this->~GenericValue(); new (this) GenericValue(b); return *this; }
818 
819     //@}
820 
821     //!@name Object
822     //@{
823 
824     //! Set this value as an empty object.
825     /*! \post IsObject() == true */
826     GenericValue& SetObject() { this->~GenericValue(); new (this) GenericValue(kObjectType); return *this; }
827 
828     //! Get the number of members in the object.
829     SizeType MemberCount() const { RAPIDJSON_ASSERT(IsObject()); return data_.o.size; }
830 
831     //! Check whether the object is empty.
832     bool ObjectEmpty() const { RAPIDJSON_ASSERT(IsObject()); return data_.o.size == 0; }
833 
834     //! Get a value from an object associated with the name.
835     /*! \pre IsObject() == true
836         \tparam T Either \c Ch or \c const \c Ch (template used for disambiguation with \ref operator[](SizeType))
837         \note In version 0.1x, if the member is not found, this function returns a null value. This makes issue 7.
838         Since 0.2, if the name is not correct, it will assert.
839         If user is unsure whether a member exists, user should use HasMember() first.
840         A better approach is to use FindMember().
841         \note Linear time complexity.
842     */
843     template <typename T>
844     RAPIDJSON_DISABLEIF_RETURN((internal::NotExpr<internal::IsSame<typename internal::RemoveConst<T>::Type, Ch> >),(GenericValue&)) operator[](T* name) {
845         GenericValue n(StringRef(name));
846         return (*this)[n];
847     }
848     template <typename T>
849     RAPIDJSON_DISABLEIF_RETURN((internal::NotExpr<internal::IsSame<typename internal::RemoveConst<T>::Type, Ch> >),(const GenericValue&)) operator[](T* name) const { return const_cast<GenericValue&>(*this)[name]; }
850 
851     //! Get a value from an object associated with the name.
852     /*! \pre IsObject() == true
853         \tparam SourceAllocator Allocator of the \c name value
854 
855         \note Compared to \ref operator[](T*), this version is faster because it does not need a StrLen().
856         And it can also handle strings with embedded null characters.
857 
858         \note Linear time complexity.
859     */
860     template <typename SourceAllocator>
861     GenericValue& operator[](const GenericValue<Encoding, SourceAllocator>& name) {
862         MemberIterator member = FindMember(name);
863         if (member != MemberEnd())
864             return member->value;
865         else {
866             RAPIDJSON_ASSERT(false);    // see above note
867             static GenericValue NullValue;
868             return NullValue;
869         }
870     }
871     template <typename SourceAllocator>
872     const GenericValue& operator[](const GenericValue<Encoding, SourceAllocator>& name) const { return const_cast<GenericValue&>(*this)[name]; }
873 
874 #if RAPIDJSON_HAS_STDSTRING
875     //! Get a value from an object associated with name (string object).
876     GenericValue& operator[](const std::basic_string<Ch>& name) { return (*this)[GenericValue(StringRef(name))]; }
877     const GenericValue& operator[](const std::basic_string<Ch>& name) const { return (*this)[GenericValue(StringRef(name))]; }
878 #endif
879 
880     //! Const member iterator
881     /*! \pre IsObject() == true */
882     ConstMemberIterator MemberBegin() const { RAPIDJSON_ASSERT(IsObject()); return ConstMemberIterator(data_.o.members); }
883     //! Const \em past-the-end member iterator
884     /*! \pre IsObject() == true */
885     ConstMemberIterator MemberEnd() const   { RAPIDJSON_ASSERT(IsObject()); return ConstMemberIterator(data_.o.members + data_.o.size); }
886     //! Member iterator
887     /*! \pre IsObject() == true */
888     MemberIterator MemberBegin()            { RAPIDJSON_ASSERT(IsObject()); return MemberIterator(data_.o.members); }
889     //! \em Past-the-end member iterator
890     /*! \pre IsObject() == true */
891     MemberIterator MemberEnd()              { RAPIDJSON_ASSERT(IsObject()); return MemberIterator(data_.o.members + data_.o.size); }
892 
893     //! Check whether a member exists in the object.
894     /*!
895         \param name Member name to be searched.
896         \pre IsObject() == true
897         \return Whether a member with that name exists.
898         \note It is better to use FindMember() directly if you need the obtain the value as well.
899         \note Linear time complexity.
900     */
901     bool HasMember(const Ch* name) const { return FindMember(name) != MemberEnd(); }
902 
903 #if RAPIDJSON_HAS_STDSTRING
904     //! Check whether a member exists in the object with string object.
905     /*!
906         \param name Member name to be searched.
907         \pre IsObject() == true
908         \return Whether a member with that name exists.
909         \note It is better to use FindMember() directly if you need the obtain the value as well.
910         \note Linear time complexity.
911     */
912     bool HasMember(const std::basic_string<Ch>& name) const { return FindMember(name) != MemberEnd(); }
913 #endif
914 
915     //! Check whether a member exists in the object with GenericValue name.
916     /*!
917         This version is faster because it does not need a StrLen(). It can also handle string with null character.
918         \param name Member name to be searched.
919         \pre IsObject() == true
920         \return Whether a member with that name exists.
921         \note It is better to use FindMember() directly if you need the obtain the value as well.
922         \note Linear time complexity.
923     */
924     template <typename SourceAllocator>
925     bool HasMember(const GenericValue<Encoding, SourceAllocator>& name) const { return FindMember(name) != MemberEnd(); }
926 
927     //! Find member by name.
928     /*!
929         \param name Member name to be searched.
930         \pre IsObject() == true
931         \return Iterator to member, if it exists.
932             Otherwise returns \ref MemberEnd().
933 
934         \note Earlier versions of Rapidjson returned a \c NULL pointer, in case
935             the requested member doesn't exist. For consistency with e.g.
936             \c std::map, this has been changed to MemberEnd() now.
937         \note Linear time complexity.
938     */
939     MemberIterator FindMember(const Ch* name) {
940         GenericValue n(StringRef(name));
941         return FindMember(n);
942     }
943 
944     ConstMemberIterator FindMember(const Ch* name) const { return const_cast<GenericValue&>(*this).FindMember(name); }
945 
946     //! Find member by name.
947     /*!
948         This version is faster because it does not need a StrLen(). It can also handle string with null character.
949         \param name Member name to be searched.
950         \pre IsObject() == true
951         \return Iterator to member, if it exists.
952             Otherwise returns \ref MemberEnd().
953 
954         \note Earlier versions of Rapidjson returned a \c NULL pointer, in case
955             the requested member doesn't exist. For consistency with e.g.
956             \c std::map, this has been changed to MemberEnd() now.
957         \note Linear time complexity.
958     */
959     template <typename SourceAllocator>
960     MemberIterator FindMember(const GenericValue<Encoding, SourceAllocator>& name) {
961         RAPIDJSON_ASSERT(IsObject());
962         RAPIDJSON_ASSERT(name.IsString());
963         MemberIterator member = MemberBegin();
964         for ( ; member != MemberEnd(); ++member)
965             if (name.StringEqual(member->name))
966                 break;
967         return member;
968     }
969     template <typename SourceAllocator> ConstMemberIterator FindMember(const GenericValue<Encoding, SourceAllocator>& name) const { return const_cast<GenericValue&>(*this).FindMember(name); }
970 
971 #if RAPIDJSON_HAS_STDSTRING
972     //! Find member by string object name.
973     /*!
974         \param name Member name to be searched.
975         \pre IsObject() == true
976         \return Iterator to member, if it exists.
977             Otherwise returns \ref MemberEnd().
978     */
979     MemberIterator FindMember(const std::basic_string<Ch>& name) { return FindMember(StringRef(name)); }
980     ConstMemberIterator FindMember(const std::basic_string<Ch>& name) const { return FindMember(StringRef(name)); }
981 #endif
982 
983     //! Add a member (name-value pair) to the object.
984     /*! \param name A string value as name of member.
985         \param value Value of any type.
986         \param allocator    Allocator for reallocating memory. It must be the same one as used before. Commonly use GenericDocument::GetAllocator().
987         \return The value itself for fluent API.
988         \note The ownership of \c name and \c value will be transferred to this object on success.
989         \pre  IsObject() && name.IsString()
990         \post name.IsNull() && value.IsNull()
991         \note Amortized Constant time complexity.
992     */
993     GenericValue& AddMember(GenericValue& name, GenericValue& value, Allocator& allocator) {
994         RAPIDJSON_ASSERT(IsObject());
995         RAPIDJSON_ASSERT(name.IsString());
996 
997         Object& o = data_.o;
998         if (o.size >= o.capacity) {
999             if (o.capacity == 0) {
1000                 o.capacity = kDefaultObjectCapacity;
1001                 o.members = reinterpret_cast<Member*>(allocator.Malloc(o.capacity * sizeof(Member)));
1002             }
1003             else {
1004                 SizeType oldCapacity = o.capacity;
1005                 o.capacity += (oldCapacity + 1) / 2; // grow by factor 1.5
1006                 o.members = reinterpret_cast<Member*>(allocator.Realloc(o.members, oldCapacity * sizeof(Member), o.capacity * sizeof(Member)));
1007             }
1008         }
1009         o.members[o.size].name.RawAssign(name);
1010         o.members[o.size].value.RawAssign(value);
1011         o.size++;
1012         return *this;
1013     }
1014 
1015     //! Add a constant string value as member (name-value pair) to the object.
1016     /*! \param name A string value as name of member.
1017         \param value constant string reference as value of member.
1018         \param allocator    Allocator for reallocating memory. It must be the same one as used before. Commonly use GenericDocument::GetAllocator().
1019         \return The value itself for fluent API.
1020         \pre  IsObject()
1021         \note This overload is needed to avoid clashes with the generic primitive type AddMember(GenericValue&,T,Allocator&) overload below.
1022         \note Amortized Constant time complexity.
1023     */
1024     GenericValue& AddMember(GenericValue& name, StringRefType value, Allocator& allocator) {
1025         GenericValue v(value);
1026         return AddMember(name, v, allocator);
1027     }
1028 
1029 #if RAPIDJSON_HAS_STDSTRING
1030     //! Add a string object as member (name-value pair) to the object.
1031     /*! \param name A string value as name of member.
1032         \param value constant string reference as value of member.
1033         \param allocator    Allocator for reallocating memory. It must be the same one as used before. Commonly use GenericDocument::GetAllocator().
1034         \return The value itself for fluent API.
1035         \pre  IsObject()
1036         \note This overload is needed to avoid clashes with the generic primitive type AddMember(GenericValue&,T,Allocator&) overload below.
1037         \note Amortized Constant time complexity.
1038     */
1039     GenericValue& AddMember(GenericValue& name, std::basic_string<Ch>& value, Allocator& allocator) {
1040         GenericValue v(value, allocator);
1041         return AddMember(name, v, allocator);
1042     }
1043 #endif
1044 
1045     //! Add any primitive value as member (name-value pair) to the object.
1046     /*! \tparam T Either \ref Type, \c int, \c unsigned, \c int64_t, \c uint64_t
1047         \param name A string value as name of member.
1048         \param value Value of primitive type \c T as value of member
1049         \param allocator Allocator for reallocating memory. Commonly use GenericDocument::GetAllocator().
1050         \return The value itself for fluent API.
1051         \pre  IsObject()
1052 
1053         \note The source type \c T explicitly disallows all pointer types,
1054             especially (\c const) \ref Ch*.  This helps avoiding implicitly
1055             referencing character strings with insufficient lifetime, use
1056             \ref AddMember(StringRefType, GenericValue&, Allocator&) or \ref
1057             AddMember(StringRefType, StringRefType, Allocator&).
1058             All other pointer types would implicitly convert to \c bool,
1059             use an explicit cast instead, if needed.
1060         \note Amortized Constant time complexity.
1061     */
1062     template <typename T>
1063     RAPIDJSON_DISABLEIF_RETURN((internal::OrExpr<internal::IsPointer<T>, internal::IsGenericValue<T> >), (GenericValue&))
1064     AddMember(GenericValue& name, T value, Allocator& allocator) {
1065         GenericValue v(value);
1066         return AddMember(name, v, allocator);
1067     }
1068 
1069 #if RAPIDJSON_HAS_CXX11_RVALUE_REFS
1070     GenericValue& AddMember(GenericValue&& name, GenericValue&& value, Allocator& allocator) {
1071         return AddMember(name, value, allocator);
1072     }
1073     GenericValue& AddMember(GenericValue&& name, GenericValue& value, Allocator& allocator) {
1074         return AddMember(name, value, allocator);
1075     }
1076     GenericValue& AddMember(GenericValue& name, GenericValue&& value, Allocator& allocator) {
1077         return AddMember(name, value, allocator);
1078     }
1079     GenericValue& AddMember(StringRefType name, GenericValue&& value, Allocator& allocator) {
1080         GenericValue n(name);
1081         return AddMember(n, value, allocator);
1082     }
1083 #endif // RAPIDJSON_HAS_CXX11_RVALUE_REFS
1084 
1085 
1086     //! Add a member (name-value pair) to the object.
1087     /*! \param name A constant string reference as name of member.
1088         \param value Value of any type.
1089         \param allocator    Allocator for reallocating memory. It must be the same one as used before. Commonly use GenericDocument::GetAllocator().
1090         \return The value itself for fluent API.
1091         \note The ownership of \c value will be transferred to this object on success.
1092         \pre  IsObject()
1093         \post value.IsNull()
1094         \note Amortized Constant time complexity.
1095     */
1096     GenericValue& AddMember(StringRefType name, GenericValue& value, Allocator& allocator) {
1097         GenericValue n(name);
1098         return AddMember(n, value, allocator);
1099     }
1100 
1101     //! Add a constant string value as member (name-value pair) to the object.
1102     /*! \param name A constant string reference as name of member.
1103         \param value constant string reference as value of member.
1104         \param allocator    Allocator for reallocating memory. It must be the same one as used before. Commonly use GenericDocument::GetAllocator().
1105         \return The value itself for fluent API.
1106         \pre  IsObject()
1107         \note This overload is needed to avoid clashes with the generic primitive type AddMember(StringRefType,T,Allocator&) overload below.
1108         \note Amortized Constant time complexity.
1109     */
1110     GenericValue& AddMember(StringRefType name, StringRefType value, Allocator& allocator) {
1111         GenericValue v(value);
1112         return AddMember(name, v, allocator);
1113     }
1114 
1115     //! Add any primitive value as member (name-value pair) to the object.
1116     /*! \tparam T Either \ref Type, \c int, \c unsigned, \c int64_t, \c uint64_t
1117         \param name A constant string reference as name of member.
1118         \param value Value of primitive type \c T as value of member
1119         \param allocator Allocator for reallocating memory. Commonly use GenericDocument::GetAllocator().
1120         \return The value itself for fluent API.
1121         \pre  IsObject()
1122 
1123         \note The source type \c T explicitly disallows all pointer types,
1124             especially (\c const) \ref Ch*.  This helps avoiding implicitly
1125             referencing character strings with insufficient lifetime, use
1126             \ref AddMember(StringRefType, GenericValue&, Allocator&) or \ref
1127             AddMember(StringRefType, StringRefType, Allocator&).
1128             All other pointer types would implicitly convert to \c bool,
1129             use an explicit cast instead, if needed.
1130         \note Amortized Constant time complexity.
1131     */
1132     template <typename T>
1133     RAPIDJSON_DISABLEIF_RETURN((internal::OrExpr<internal::IsPointer<T>, internal::IsGenericValue<T> >), (GenericValue&))
1134     AddMember(StringRefType name, T value, Allocator& allocator) {
1135         GenericValue n(name);
1136         return AddMember(n, value, allocator);
1137     }
1138 
1139     //! Remove all members in the object.
1140     /*! This function do not deallocate memory in the object, i.e. the capacity is unchanged.
1141         \note Linear time complexity.
1142     */
1143     void RemoveAllMembers() {
1144         RAPIDJSON_ASSERT(IsObject());
1145         for (MemberIterator m = MemberBegin(); m != MemberEnd(); ++m)
1146             m->~Member();
1147         data_.o.size = 0;
1148     }
1149 
1150     //! Remove a member in object by its name.
1151     /*! \param name Name of member to be removed.
1152         \return Whether the member existed.
1153         \note This function may reorder the object members. Use \ref
1154             EraseMember(ConstMemberIterator) if you need to preserve the
1155             relative order of the remaining members.
1156         \note Linear time complexity.
1157     */
1158     bool RemoveMember(const Ch* name) {
1159         GenericValue n(StringRef(name));
1160         return RemoveMember(n);
1161     }
1162 
1163 #if RAPIDJSON_HAS_STDSTRING
1164     bool RemoveMember(const std::basic_string<Ch>& name) { return RemoveMember(GenericValue(StringRef(name))); }
1165 #endif
1166 
1167     template <typename SourceAllocator>
1168     bool RemoveMember(const GenericValue<Encoding, SourceAllocator>& name) {
1169         MemberIterator m = FindMember(name);
1170         if (m != MemberEnd()) {
1171             RemoveMember(m);
1172             return true;
1173         }
1174         else
1175             return false;
1176     }
1177 
1178     //! Remove a member in object by iterator.
1179     /*! \param m member iterator (obtained by FindMember() or MemberBegin()).
1180         \return the new iterator after removal.
1181         \note This function may reorder the object members. Use \ref
1182             EraseMember(ConstMemberIterator) if you need to preserve the
1183             relative order of the remaining members.
1184         \note Constant time complexity.
1185     */
1186     MemberIterator RemoveMember(MemberIterator m) {
1187         RAPIDJSON_ASSERT(IsObject());
1188         RAPIDJSON_ASSERT(data_.o.size > 0);
1189         RAPIDJSON_ASSERT(data_.o.members != 0);
1190         RAPIDJSON_ASSERT(m >= MemberBegin() && m < MemberEnd());
1191 
1192         MemberIterator last(data_.o.members + (data_.o.size - 1));
1193         if (data_.o.size > 1 && m != last) {
1194             // Move the last one to this place
1195             *m = *last;
1196         }
1197         else {
1198             // Only one left, just destroy
1199             m->~Member();
1200         }
1201         --data_.o.size;
1202         return m;
1203     }
1204 
1205     //! Remove a member from an object by iterator.
1206     /*! \param pos iterator to the member to remove
1207         \pre IsObject() == true && \ref MemberBegin() <= \c pos < \ref MemberEnd()
1208         \return Iterator following the removed element.
1209             If the iterator \c pos refers to the last element, the \ref MemberEnd() iterator is returned.
1210         \note This function preserves the relative order of the remaining object
1211             members. If you do not need this, use the more efficient \ref RemoveMember(MemberIterator).
1212         \note Linear time complexity.
1213     */
1214     MemberIterator EraseMember(ConstMemberIterator pos) {
1215         return EraseMember(pos, pos +1);
1216     }
1217 
1218     //! Remove members in the range [first, last) from an object.
1219     /*! \param first iterator to the first member to remove
1220         \param last  iterator following the last member to remove
1221         \pre IsObject() == true && \ref MemberBegin() <= \c first <= \c last <= \ref MemberEnd()
1222         \return Iterator following the last removed element.
1223         \note This function preserves the relative order of the remaining object
1224             members.
1225         \note Linear time complexity.
1226     */
1227     MemberIterator EraseMember(ConstMemberIterator first, ConstMemberIterator last) {
1228         RAPIDJSON_ASSERT(IsObject());
1229         RAPIDJSON_ASSERT(data_.o.size > 0);
1230         RAPIDJSON_ASSERT(data_.o.members != 0);
1231         RAPIDJSON_ASSERT(first >= MemberBegin());
1232         RAPIDJSON_ASSERT(first <= last);
1233         RAPIDJSON_ASSERT(last <= MemberEnd());
1234 
1235         MemberIterator pos = MemberBegin() + (first - MemberBegin());
1236         for (MemberIterator itr = pos; itr != last; ++itr)
1237             itr->~Member();
1238         std::memmove(&*pos, &*last, (MemberEnd() - last) * sizeof(Member));
1239         data_.o.size -= (last - first);
1240         return pos;
1241     }
1242 
1243     //! Erase a member in object by its name.
1244     /*! \param name Name of member to be removed.
1245         \return Whether the member existed.
1246         \note Linear time complexity.
1247     */
1248     bool EraseMember(const Ch* name) {
1249         GenericValue n(StringRef(name));
1250         return EraseMember(n);
1251     }
1252 
1253 #if RAPIDJSON_HAS_STDSTRING
1254     bool EraseMember(const std::basic_string<Ch>& name) { return EraseMember(GenericValue(StringRef(name))); }
1255 #endif
1256 
1257     template <typename SourceAllocator>
1258     bool EraseMember(const GenericValue<Encoding, SourceAllocator>& name) {
1259         MemberIterator m = FindMember(name);
1260         if (m != MemberEnd()) {
1261             EraseMember(m);
1262             return true;
1263         }
1264         else
1265             return false;
1266     }
1267 
1268     //@}
1269 
1270     //!@name Array
1271     //@{
1272 
1273     //! Set this value as an empty array.
1274     /*! \post IsArray == true */
1275     GenericValue& SetArray() {  this->~GenericValue(); new (this) GenericValue(kArrayType); return *this; }
1276 
1277     //! Get the number of elements in array.
1278     SizeType Size() const { RAPIDJSON_ASSERT(IsArray()); return data_.a.size; }
1279 
1280     //! Get the capacity of array.
1281     SizeType Capacity() const { RAPIDJSON_ASSERT(IsArray()); return data_.a.capacity; }
1282 
1283     //! Check whether the array is empty.
1284     bool Empty() const { RAPIDJSON_ASSERT(IsArray()); return data_.a.size == 0; }
1285 
1286     //! Remove all elements in the array.
1287     /*! This function do not deallocate memory in the array, i.e. the capacity is unchanged.
1288         \note Linear time complexity.
1289     */
1290     void Clear() {
1291         RAPIDJSON_ASSERT(IsArray());
1292         for (SizeType i = 0; i < data_.a.size; ++i)
1293             data_.a.elements[i].~GenericValue();
1294         data_.a.size = 0;
1295     }
1296 
1297     //! Get an element from array by index.
1298     /*! \pre IsArray() == true
1299         \param index Zero-based index of element.
1300         \see operator[](T*)
1301     */
1302     GenericValue& operator[](SizeType index) {
1303         RAPIDJSON_ASSERT(IsArray());
1304         RAPIDJSON_ASSERT(index < data_.a.size);
1305         return data_.a.elements[index];
1306     }
1307     const GenericValue& operator[](SizeType index) const { return const_cast<GenericValue&>(*this)[index]; }
1308 
1309     //! Element iterator
1310     /*! \pre IsArray() == true */
1311     ValueIterator Begin() { RAPIDJSON_ASSERT(IsArray()); return data_.a.elements; }
1312     //! \em Past-the-end element iterator
1313     /*! \pre IsArray() == true */
1314     ValueIterator End() { RAPIDJSON_ASSERT(IsArray()); return data_.a.elements + data_.a.size; }
1315     //! Constant element iterator
1316     /*! \pre IsArray() == true */
1317     ConstValueIterator Begin() const { return const_cast<GenericValue&>(*this).Begin(); }
1318     //! Constant \em past-the-end element iterator
1319     /*! \pre IsArray() == true */
1320     ConstValueIterator End() const { return const_cast<GenericValue&>(*this).End(); }
1321 
1322     //! Request the array to have enough capacity to store elements.
1323     /*! \param newCapacity  The capacity that the array at least need to have.
1324         \param allocator    Allocator for reallocating memory. It must be the same one as used before. Commonly use GenericDocument::GetAllocator().
1325         \return The value itself for fluent API.
1326         \note Linear time complexity.
1327     */
1328     GenericValue& Reserve(SizeType newCapacity, Allocator &allocator) {
1329         RAPIDJSON_ASSERT(IsArray());
1330         if (newCapacity > data_.a.capacity) {
1331             data_.a.elements = (GenericValue*)allocator.Realloc(data_.a.elements, data_.a.capacity * sizeof(GenericValue), newCapacity * sizeof(GenericValue));
1332             data_.a.capacity = newCapacity;
1333         }
1334         return *this;
1335     }
1336 
1337     //! Append a GenericValue at the end of the array.
1338     /*! \param value        Value to be appended.
1339         \param allocator    Allocator for reallocating memory. It must be the same one as used before. Commonly use GenericDocument::GetAllocator().
1340         \pre IsArray() == true
1341         \post value.IsNull() == true
1342         \return The value itself for fluent API.
1343         \note The ownership of \c value will be transferred to this array on success.
1344         \note If the number of elements to be appended is known, calls Reserve() once first may be more efficient.
1345         \note Amortized constant time complexity.
1346     */
1347     GenericValue& PushBack(GenericValue& value, Allocator& allocator) {
1348         RAPIDJSON_ASSERT(IsArray());
1349         if (data_.a.size >= data_.a.capacity)
1350             Reserve(data_.a.capacity == 0 ? kDefaultArrayCapacity : (data_.a.capacity + (data_.a.capacity + 1) / 2), allocator);
1351         data_.a.elements[data_.a.size++].RawAssign(value);
1352         return *this;
1353     }
1354 
1355 #if RAPIDJSON_HAS_CXX11_RVALUE_REFS
1356     GenericValue& PushBack(GenericValue&& value, Allocator& allocator) {
1357         return PushBack(value, allocator);
1358     }
1359 #endif // RAPIDJSON_HAS_CXX11_RVALUE_REFS
1360 
1361     //! Append a constant string reference at the end of the array.
1362     /*! \param value        Constant string reference to be appended.
1363         \param allocator    Allocator for reallocating memory. It must be the same one used previously. Commonly use GenericDocument::GetAllocator().
1364         \pre IsArray() == true
1365         \return The value itself for fluent API.
1366         \note If the number of elements to be appended is known, calls Reserve() once first may be more efficient.
1367         \note Amortized constant time complexity.
1368         \see GenericStringRef
1369     */
1370     GenericValue& PushBack(StringRefType value, Allocator& allocator) {
1371         return (*this).template PushBack<StringRefType>(value, allocator);
1372     }
1373 
1374     //! Append a primitive value at the end of the array.
1375     /*! \tparam T Either \ref Type, \c int, \c unsigned, \c int64_t, \c uint64_t
1376         \param value Value of primitive type T to be appended.
1377         \param allocator    Allocator for reallocating memory. It must be the same one as used before. Commonly use GenericDocument::GetAllocator().
1378         \pre IsArray() == true
1379         \return The value itself for fluent API.
1380         \note If the number of elements to be appended is known, calls Reserve() once first may be more efficient.
1381 
1382         \note The source type \c T explicitly disallows all pointer types,
1383             especially (\c const) \ref Ch*.  This helps avoiding implicitly
1384             referencing character strings with insufficient lifetime, use
1385             \ref PushBack(GenericValue&, Allocator&) or \ref
1386             PushBack(StringRefType, Allocator&).
1387             All other pointer types would implicitly convert to \c bool,
1388             use an explicit cast instead, if needed.
1389         \note Amortized constant time complexity.
1390     */
1391     template <typename T>
1392     RAPIDJSON_DISABLEIF_RETURN((internal::OrExpr<internal::IsPointer<T>, internal::IsGenericValue<T> >), (GenericValue&))
1393     PushBack(T value, Allocator& allocator) {
1394         GenericValue v(value);
1395         return PushBack(v, allocator);
1396     }
1397 
1398     //! Remove the last element in the array.
1399     /*!
1400         \note Constant time complexity.
1401     */
1402     GenericValue& PopBack() {
1403         RAPIDJSON_ASSERT(IsArray());
1404         RAPIDJSON_ASSERT(!Empty());
1405         data_.a.elements[--data_.a.size].~GenericValue();
1406         return *this;
1407     }
1408 
1409     //! Remove an element of array by iterator.
1410     /*!
1411         \param pos iterator to the element to remove
1412         \pre IsArray() == true && \ref Begin() <= \c pos < \ref End()
1413         \return Iterator following the removed element. If the iterator pos refers to the last element, the End() iterator is returned.
1414         \note Linear time complexity.
1415     */
1416     ValueIterator Erase(ConstValueIterator pos) {
1417         return Erase(pos, pos + 1);
1418     }
1419 
1420     //! Remove elements in the range [first, last) of the array.
1421     /*!
1422         \param first iterator to the first element to remove
1423         \param last  iterator following the last element to remove
1424         \pre IsArray() == true && \ref Begin() <= \c first <= \c last <= \ref End()
1425         \return Iterator following the last removed element.
1426         \note Linear time complexity.
1427     */
1428     ValueIterator Erase(ConstValueIterator first, ConstValueIterator last) {
1429         RAPIDJSON_ASSERT(IsArray());
1430         RAPIDJSON_ASSERT(data_.a.size > 0);
1431         RAPIDJSON_ASSERT(data_.a.elements != 0);
1432         RAPIDJSON_ASSERT(first >= Begin());
1433         RAPIDJSON_ASSERT(first <= last);
1434         RAPIDJSON_ASSERT(last <= End());
1435         ValueIterator pos = Begin() + (first - Begin());
1436         for (ValueIterator itr = pos; itr != last; ++itr)
1437             itr->~GenericValue();
1438         std::memmove(pos, last, (End() - last) * sizeof(GenericValue));
1439         data_.a.size -= (last - first);
1440         return pos;
1441     }
1442 
1443     //@}
1444 
1445     //!@name Number
1446     //@{
1447 
1448     int GetInt() const          { RAPIDJSON_ASSERT(flags_ & kIntFlag);   return data_.n.i.i;   }
1449     unsigned GetUint() const    { RAPIDJSON_ASSERT(flags_ & kUintFlag);  return data_.n.u.u;   }
1450     int64_t GetInt64() const    { RAPIDJSON_ASSERT(flags_ & kInt64Flag); return data_.n.i64; }
1451     uint64_t GetUint64() const  { RAPIDJSON_ASSERT(flags_ & kUint64Flag); return data_.n.u64; }
1452 
1453     double GetDouble() const {
1454         RAPIDJSON_ASSERT(IsNumber());
1455         if ((flags_ & kDoubleFlag) != 0)                return data_.n.d;   // exact type, no conversion.
1456         if ((flags_ & kIntFlag) != 0)                   return data_.n.i.i; // int -> double
1457         if ((flags_ & kUintFlag) != 0)                  return data_.n.u.u; // unsigned -> double
1458         if ((flags_ & kInt64Flag) != 0)                 return (double)data_.n.i64; // int64_t -> double (may lose precision)
1459         RAPIDJSON_ASSERT((flags_ & kUint64Flag) != 0);  return (double)data_.n.u64; // uint64_t -> double (may lose precision)
1460     }
1461 
1462     GenericValue& SetInt(int i)             { this->~GenericValue(); new (this) GenericValue(i);    return *this; }
1463     GenericValue& SetUint(unsigned u)       { this->~GenericValue(); new (this) GenericValue(u);    return *this; }
1464     GenericValue& SetInt64(int64_t i64)     { this->~GenericValue(); new (this) GenericValue(i64);  return *this; }
1465     GenericValue& SetUint64(uint64_t u64)   { this->~GenericValue(); new (this) GenericValue(u64);  return *this; }
1466     GenericValue& SetDouble(double d)       { this->~GenericValue(); new (this) GenericValue(d);    return *this; }
1467 
1468     //@}
1469 
1470     //!@name String
1471     //@{
1472 
1473     const Ch* GetString() const { RAPIDJSON_ASSERT(IsString()); return ((flags_ & kInlineStrFlag) ? data_.ss.str : data_.s.str); }
1474 
1475     //! Get the length of string.
1476     /*! Since rapidjson permits "\\u0000" in the json string, strlen(v.GetString()) may not equal to v.GetStringLength().
1477     */
1478     SizeType GetStringLength() const { RAPIDJSON_ASSERT(IsString()); return ((flags_ & kInlineStrFlag) ? (data_.ss.GetLength()) : data_.s.length); }
1479 
1480     //! Set this value as a string without copying source string.
1481     /*! This version has better performance with supplied length, and also support string containing null character.
1482         \param s source string pointer.
1483         \param length The length of source string, excluding the trailing null terminator.
1484         \return The value itself for fluent API.
1485         \post IsString() == true && GetString() == s && GetStringLength() == length
1486         \see SetString(StringRefType)
1487     */
1488     GenericValue& SetString(const Ch* s, SizeType length) { return SetString(StringRef(s, length)); }
1489 
1490     //! Set this value as a string without copying source string.
1491     /*! \param s source string reference
1492         \return The value itself for fluent API.
1493         \post IsString() == true && GetString() == s && GetStringLength() == s.length
1494     */
1495     GenericValue& SetString(StringRefType s) { this->~GenericValue(); SetStringRaw(s); return *this; }
1496 
1497     //! Set this value as a string by copying from source string.
1498     /*! This version has better performance with supplied length, and also support string containing null character.
1499         \param s source string.
1500         \param length The length of source string, excluding the trailing null terminator.
1501         \param allocator Allocator for allocating copied buffer. Commonly use GenericDocument::GetAllocator().
1502         \return The value itself for fluent API.
1503         \post IsString() == true && GetString() != s && strcmp(GetString(),s) == 0 && GetStringLength() == length
1504     */
1505     GenericValue& SetString(const Ch* s, SizeType length, Allocator& allocator) { this->~GenericValue(); SetStringRaw(StringRef(s, length), allocator); return *this; }
1506 
1507     //! Set this value as a string by copying from source string.
1508     /*! \param s source string.
1509         \param allocator Allocator for allocating copied buffer. Commonly use GenericDocument::GetAllocator().
1510         \return The value itself for fluent API.
1511         \post IsString() == true && GetString() != s && strcmp(GetString(),s) == 0 && GetStringLength() == length
1512     */
1513     GenericValue& SetString(const Ch* s, Allocator& allocator) { return SetString(s, internal::StrLen(s), allocator); }
1514 
1515 #if RAPIDJSON_HAS_STDSTRING
1516     //! Set this value as a string by copying from source string.
1517     /*! \param s source string.
1518         \param allocator Allocator for allocating copied buffer. Commonly use GenericDocument::GetAllocator().
1519         \return The value itself for fluent API.
1520         \post IsString() == true && GetString() != s.data() && strcmp(GetString(),s.data() == 0 && GetStringLength() == s.size()
1521         \note Requires the definition of the preprocessor symbol \ref RAPIDJSON_HAS_STDSTRING.
1522     */
1523     GenericValue& SetString(const std::basic_string<Ch>& s, Allocator& allocator) { return SetString(s.data(), SizeType(s.size()), allocator); }
1524 #endif
1525 
1526     //@}
1527 
1528     //! Generate events of this value to a Handler.
1529     /*! This function adopts the GoF visitor pattern.
1530         Typical usage is to output this JSON value as JSON text via Writer, which is a Handler.
1531         It can also be used to deep clone this value via GenericDocument, which is also a Handler.
1532         \tparam Handler type of handler.
1533         \param handler An object implementing concept Handler.
1534     */
1535     template <typename Handler>
1536     bool Accept(Handler& handler) const {
1537         switch(GetType()) {
1538         case kNullType:     return handler.Null();
1539         case kFalseType:    return handler.Bool(false);
1540         case kTrueType:     return handler.Bool(true);
1541 
1542         case kObjectType:
1543             if (!handler.StartObject())
1544                 return false;
1545             for (ConstMemberIterator m = MemberBegin(); m != MemberEnd(); ++m) {
1546                 RAPIDJSON_ASSERT(m->name.IsString()); // User may change the type of name by MemberIterator.
1547                 if (!handler.Key(m->name.GetString(), m->name.GetStringLength(), (m->name.flags_ & kCopyFlag) != 0))
1548                     return false;
1549                 if (!m->value.Accept(handler))
1550                     return false;
1551             }
1552             return handler.EndObject(data_.o.size);
1553 
1554         case kArrayType:
1555             if (!handler.StartArray())
1556                 return false;
1557             for (GenericValue* v = data_.a.elements; v != data_.a.elements + data_.a.size; ++v)
1558                 if (!v->Accept(handler))
1559                     return false;
1560             return handler.EndArray(data_.a.size);
1561 
1562         case kStringType:
1563             return handler.String(GetString(), GetStringLength(), (flags_ & kCopyFlag) != 0);
1564 
1565         default:
1566             RAPIDJSON_ASSERT(GetType() == kNumberType);
1567             if (IsInt())            return handler.Int(data_.n.i.i);
1568             else if (IsUint())      return handler.Uint(data_.n.u.u);
1569             else if (IsInt64())     return handler.Int64(data_.n.i64);
1570             else if (IsUint64())    return handler.Uint64(data_.n.u64);
1571             else                    return handler.Double(data_.n.d);
1572         }
1573     }
1574 
1575 private:
1576     template <typename, typename> friend class GenericValue;
1577     template <typename, typename, typename> friend class GenericDocument;
1578 
1579     enum {
1580         kBoolFlag = 0x100,
1581         kNumberFlag = 0x200,
1582         kIntFlag = 0x400,
1583         kUintFlag = 0x800,
1584         kInt64Flag = 0x1000,
1585         kUint64Flag = 0x2000,
1586         kDoubleFlag = 0x4000,
1587         kStringFlag = 0x100000,
1588         kCopyFlag = 0x200000,
1589         kInlineStrFlag = 0x400000,
1590 
1591         // Initial flags of different types.
1592         kNullFlag = kNullType,
1593         kTrueFlag = kTrueType | kBoolFlag,
1594         kFalseFlag = kFalseType | kBoolFlag,
1595         kNumberIntFlag = kNumberType | kNumberFlag | kIntFlag | kInt64Flag,
1596         kNumberUintFlag = kNumberType | kNumberFlag | kUintFlag | kUint64Flag | kInt64Flag,
1597         kNumberInt64Flag = kNumberType | kNumberFlag | kInt64Flag,
1598         kNumberUint64Flag = kNumberType | kNumberFlag | kUint64Flag,
1599         kNumberDoubleFlag = kNumberType | kNumberFlag | kDoubleFlag,
1600         kNumberAnyFlag = kNumberType | kNumberFlag | kIntFlag | kInt64Flag | kUintFlag | kUint64Flag | kDoubleFlag,
1601         kConstStringFlag = kStringType | kStringFlag,
1602         kCopyStringFlag = kStringType | kStringFlag | kCopyFlag,
1603         kShortStringFlag = kStringType | kStringFlag | kCopyFlag | kInlineStrFlag,
1604         kObjectFlag = kObjectType,
1605         kArrayFlag = kArrayType,
1606 
1607         kTypeMask = 0xFF    // bitwise-and with mask of 0xFF can be optimized by compiler
1608     };
1609 
1610     static const SizeType kDefaultArrayCapacity = 16;
1611     static const SizeType kDefaultObjectCapacity = 16;
1612 
1613     struct String {
1614         const Ch* str;
1615         SizeType length;
1616         unsigned hashcode;  //!< reserved
1617     };  // 12 bytes in 32-bit mode, 16 bytes in 64-bit mode
1618 
1619     // implementation detail: ShortString can represent zero-terminated strings up to MaxSize chars
1620     // (excluding the terminating zero) and store a value to determine the length of the contained
1621     // string in the last character str[LenPos] by storing "MaxSize - length" there. If the string
1622     // to store has the maximal length of MaxSize then str[LenPos] will be 0 and therefore act as
1623     // the string terminator as well. For getting the string length back from that value just use
1624     // "MaxSize - str[LenPos]".
1625     // This allows to store 11-chars strings in 32-bit mode and 15-chars strings in 64-bit mode
1626     // inline (for `UTF8`-encoded strings).
1627     struct ShortString {
1628         enum { MaxChars = sizeof(String) / sizeof(Ch), MaxSize = MaxChars - 1, LenPos = MaxSize };
1629         Ch str[MaxChars];
1630 
1631         inline static bool Usable(SizeType len) { return            (MaxSize >= len); }
1632         inline void     SetLength(SizeType len) { str[LenPos] = (Ch)(MaxSize -  len); }
1633         inline SizeType GetLength() const       { return  (SizeType)(MaxSize -  str[LenPos]); }
1634     };  // at most as many bytes as "String" above => 12 bytes in 32-bit mode, 16 bytes in 64-bit mode
1635 
1636     // By using proper binary layout, retrieval of different integer types do not need conversions.
1637     union Number {
1638 #if RAPIDJSON_ENDIAN == RAPIDJSON_LITTLEENDIAN
1639         struct I {
1640             int i;
1641             char padding[4];
1642         }i;
1643         struct U {
1644             unsigned u;
1645             char padding2[4];
1646         }u;
1647 #else
1648         struct I {
1649             char padding[4];
1650             int i;
1651         }i;
1652         struct U {
1653             char padding2[4];
1654             unsigned u;
1655         }u;
1656 #endif
1657         int64_t i64;
1658         uint64_t u64;
1659         double d;
1660     };  // 8 bytes
1661 
1662     struct Object {
1663         Member* members;
1664         SizeType size;
1665         SizeType capacity;
1666     };  // 12 bytes in 32-bit mode, 16 bytes in 64-bit mode
1667 
1668     struct Array {
1669         GenericValue* elements;
1670         SizeType size;
1671         SizeType capacity;
1672     };  // 12 bytes in 32-bit mode, 16 bytes in 64-bit mode
1673 
1674     union Data {
1675         String s;
1676         ShortString ss;
1677         Number n;
1678         Object o;
1679         Array a;
1680     };  // 12 bytes in 32-bit mode, 16 bytes in 64-bit mode
1681 
1682     // Initialize this value as array with initial data, without calling destructor.
1683     void SetArrayRaw(GenericValue* values, SizeType count, Allocator& allocator) {
1684         flags_ = kArrayFlag;
1685         if (count) {
1686             data_.a.elements = (GenericValue*)allocator.Malloc(count * sizeof(GenericValue));
1687             std::memcpy(data_.a.elements, values, count * sizeof(GenericValue));
1688         }
1689         else
1690             data_.a.elements = NULL;
1691         data_.a.size = data_.a.capacity = count;
1692     }
1693 
1694     //! Initialize this value as object with initial data, without calling destructor.
1695     void SetObjectRaw(Member* members, SizeType count, Allocator& allocator) {
1696         flags_ = kObjectFlag;
1697         if (count) {
1698             data_.o.members = (Member*)allocator.Malloc(count * sizeof(Member));
1699             std::memcpy(data_.o.members, members, count * sizeof(Member));
1700         }
1701         else
1702             data_.o.members = NULL;
1703         data_.o.size = data_.o.capacity = count;
1704     }
1705 
1706     //! Initialize this value as constant string, without calling destructor.
1707     void SetStringRaw(StringRefType s) RAPIDJSON_NOEXCEPT {
1708         flags_ = kConstStringFlag;
1709         data_.s.str = s;
1710         data_.s.length = s.length;
1711     }
1712 
1713     //! Initialize this value as copy string with initial data, without calling destructor.
1714     void SetStringRaw(StringRefType s, Allocator& allocator) {
1715         Ch* str = NULL;
1716         if(ShortString::Usable(s.length)) {
1717             flags_ = kShortStringFlag;
1718             data_.ss.SetLength(s.length);
1719             str = data_.ss.str;
1720         } else {
1721             flags_ = kCopyStringFlag;
1722             data_.s.length = s.length;
1723             str = (Ch *)allocator.Malloc((s.length + 1) * sizeof(Ch));
1724             data_.s.str = str;
1725         }
1726         std::memcpy(str, s, s.length * sizeof(Ch));
1727         str[s.length] = '\0';
1728     }
1729 
1730     //! Assignment without calling destructor
1731     void RawAssign(GenericValue& rhs) RAPIDJSON_NOEXCEPT {
1732         data_ = rhs.data_;
1733         flags_ = rhs.flags_;
1734         rhs.flags_ = kNullFlag;
1735     }
1736 
1737     template <typename SourceAllocator>
1738     bool StringEqual(const GenericValue<Encoding, SourceAllocator>& rhs) const {
1739         RAPIDJSON_ASSERT(IsString());
1740         RAPIDJSON_ASSERT(rhs.IsString());
1741 
1742         const SizeType len1 = GetStringLength();
1743         const SizeType len2 = rhs.GetStringLength();
1744         if(len1 != len2) { return false; }
1745 
1746         const Ch* const str1 = GetString();
1747         const Ch* const str2 = rhs.GetString();
1748         if(str1 == str2) { return true; } // fast path for constant string
1749 
1750         return (std::memcmp(str1, str2, sizeof(Ch) * len1) == 0);
1751     }
1752 
1753     Data data_;
1754     unsigned flags_;
1755 };
1756 
1757 //! GenericValue with UTF8 encoding
1758 typedef GenericValue<UTF8<> > Value;
1759 
1760 ///////////////////////////////////////////////////////////////////////////////
1761 // GenericDocument
1762 
1763 //! A document for parsing JSON text as DOM.
1764 /*!
1765     \note implements Handler concept
1766     \tparam Encoding Encoding for both parsing and string storage.
1767     \tparam Allocator Allocator for allocating memory for the DOM
1768     \tparam StackAllocator Allocator for allocating memory for stack during parsing.
1769     \warning Although GenericDocument inherits from GenericValue, the API does \b not provide any virtual functions, especially no virtual destructor.  To avoid memory leaks, do not \c delete a GenericDocument object via a pointer to a GenericValue.
1770 */
1771 template <typename Encoding, typename Allocator = MemoryPoolAllocator<>, typename StackAllocator = CrtAllocator>
1772 class GenericDocument : public GenericValue<Encoding, Allocator> {
1773 public:
1774     typedef typename Encoding::Ch Ch;                       //!< Character type derived from Encoding.
1775     typedef GenericValue<Encoding, Allocator> ValueType;    //!< Value type of the document.
1776     typedef Allocator AllocatorType;                        //!< Allocator type from template parameter.
1777 
1778     //! Constructor
1779     /*! Creates an empty document of specified type.
1780         \param type             Mandatory type of object to create.
1781         \param allocator        Optional allocator for allocating memory.
1782         \param stackCapacity    Optional initial capacity of stack in bytes.
1783         \param stackAllocator   Optional allocator for allocating memory for stack.
1784     */
1785     explicit GenericDocument(Type type, Allocator* allocator = 0, size_t stackCapacity = kDefaultStackCapacity, StackAllocator* stackAllocator = 0) :
1786         GenericValue<Encoding, Allocator>(type),  allocator_(allocator), ownAllocator_(0), stack_(stackAllocator, stackCapacity), parseResult_()
1787     {
1788         if (!allocator_)
1789             ownAllocator_ = allocator_ = RAPIDJSON_NEW(Allocator());
1790     }
1791 
1792     //! Constructor
1793     /*! Creates an empty document which type is Null.
1794         \param allocator        Optional allocator for allocating memory.
1795         \param stackCapacity    Optional initial capacity of stack in bytes.
1796         \param stackAllocator   Optional allocator for allocating memory for stack.
1797     */
1798     GenericDocument(Allocator* allocator = 0, size_t stackCapacity = kDefaultStackCapacity, StackAllocator* stackAllocator = 0) :
1799         allocator_(allocator), ownAllocator_(0), stack_(stackAllocator, stackCapacity), parseResult_()
1800     {
1801         if (!allocator_)
1802             ownAllocator_ = allocator_ = RAPIDJSON_NEW(Allocator());
1803     }
1804 
1805 #if RAPIDJSON_HAS_CXX11_RVALUE_REFS
1806     //! Move constructor in C++11
1807     GenericDocument(GenericDocument&& rhs) RAPIDJSON_NOEXCEPT
1808         : ValueType(std::forward<ValueType>(rhs)), // explicit cast to avoid prohibited move from Document
1809           allocator_(rhs.allocator_),
1810           ownAllocator_(rhs.ownAllocator_),
1811           stack_(std::move(rhs.stack_)),
1812           parseResult_(rhs.parseResult_)
1813     {
1814         rhs.allocator_ = 0;
1815         rhs.ownAllocator_ = 0;
1816         rhs.parseResult_ = ParseResult();
1817     }
1818 #endif
1819 
1820     ~GenericDocument() {
1821         Destroy();
1822     }
1823 
1824 #if RAPIDJSON_HAS_CXX11_RVALUE_REFS
1825     //! Move assignment in C++11
1826     GenericDocument& operator=(GenericDocument&& rhs) RAPIDJSON_NOEXCEPT
1827     {
1828         // The cast to ValueType is necessary here, because otherwise it would
1829         // attempt to call GenericValue's templated assignment operator.
1830         ValueType::operator=(std::forward<ValueType>(rhs));
1831 
1832         // Calling the destructor here would prematurely call stack_'s destructor
1833         Destroy();
1834 
1835         allocator_ = rhs.allocator_;
1836         ownAllocator_ = rhs.ownAllocator_;
1837         stack_ = std::move(rhs.stack_);
1838         parseResult_ = rhs.parseResult_;
1839 
1840         rhs.allocator_ = 0;
1841         rhs.ownAllocator_ = 0;
1842         rhs.parseResult_ = ParseResult();
1843 
1844         return *this;
1845     }
1846 #endif
1847 
1848     //! Exchange the contents of this document with those of another.
1849     /*!
1850         \param other Another document.
1851         \note Constant complexity.
1852         \see GenericValue::Swap
1853     */
1854     GenericDocument& Swap(GenericDocument& rhs) RAPIDJSON_NOEXCEPT {
1855         ValueType::Swap(rhs);
1856         stack_.Swap(rhs.stack_);
1857         internal::Swap(allocator_, rhs.allocator_);
1858         internal::Swap(ownAllocator_, rhs.ownAllocator_);
1859         internal::Swap(parseResult_, rhs.parseResult_);
1860         return *this;
1861     }
1862 
1863     //! free-standing swap function helper
1864     /*!
1865         Helper function to enable support for common swap implementation pattern based on \c std::swap:
1866         \code
1867         void swap(MyClass& a, MyClass& b) {
1868             using std::swap;
1869             swap(a.doc, b.doc);
1870             // ...
1871         }
1872         \endcode
1873         \see Swap()
1874      */
1875     friend inline void swap(GenericDocument& a, GenericDocument& b) RAPIDJSON_NOEXCEPT { a.Swap(b); }
1876 
1877     //!@name Parse from stream
1878     //!@{
1879 
1880     //! Parse JSON text from an input stream (with Encoding conversion)
1881     /*! \tparam parseFlags Combination of \ref ParseFlag.
1882         \tparam SourceEncoding Encoding of input stream
1883         \tparam InputStream Type of input stream, implementing Stream concept
1884         \param is Input stream to be parsed.
1885         \return The document itself for fluent API.
1886     */
1887     template <unsigned parseFlags, typename SourceEncoding, typename InputStream>
1888     GenericDocument& ParseStream(InputStream& is) {
1889         ValueType::SetNull(); // Remove existing root if exist
1890         GenericReader<SourceEncoding, Encoding, StackAllocator> reader(
1891             stack_.HasAllocator() ? &stack_.GetAllocator() : 0);
1892         ClearStackOnExit scope(*this);
1893         parseResult_ = reader.template Parse<parseFlags>(is, *this);
1894         if (parseResult_) {
1895             RAPIDJSON_ASSERT(stack_.GetSize() == sizeof(ValueType)); // Got one and only one root object
1896             this->RawAssign(*stack_.template Pop<ValueType>(1));    // Add this-> to prevent issue 13.
1897         }
1898         return *this;
1899     }
1900 
1901     //! Parse JSON text from an input stream
1902     /*! \tparam parseFlags Combination of \ref ParseFlag.
1903         \tparam InputStream Type of input stream, implementing Stream concept
1904         \param is Input stream to be parsed.
1905         \return The document itself for fluent API.
1906     */
1907     template <unsigned parseFlags, typename InputStream>
1908     GenericDocument& ParseStream(InputStream& is) {
1909         return ParseStream<parseFlags, Encoding, InputStream>(is);
1910     }
1911 
1912     //! Parse JSON text from an input stream (with \ref kParseDefaultFlags)
1913     /*! \tparam InputStream Type of input stream, implementing Stream concept
1914         \param is Input stream to be parsed.
1915         \return The document itself for fluent API.
1916     */
1917     template <typename InputStream>
1918     GenericDocument& ParseStream(InputStream& is) {
1919         return ParseStream<kParseDefaultFlags, Encoding, InputStream>(is);
1920     }
1921     //!@}
1922 
1923     //!@name Parse in-place from mutable string
1924     //!@{
1925 
1926     //! Parse JSON text from a mutable string
1927     /*! \tparam parseFlags Combination of \ref ParseFlag.
1928         \param str Mutable zero-terminated string to be parsed.
1929         \return The document itself for fluent API.
1930     */
1931     template <unsigned parseFlags>
1932     GenericDocument& ParseInsitu(Ch* str) {
1933         GenericInsituStringStream<Encoding> s(str);
1934         return ParseStream<parseFlags | kParseInsituFlag>(s);
1935     }
1936 
1937     //! Parse JSON text from a mutable string (with \ref kParseDefaultFlags)
1938     /*! \param str Mutable zero-terminated string to be parsed.
1939         \return The document itself for fluent API.
1940     */
1941     GenericDocument& ParseInsitu(Ch* str) {
1942         return ParseInsitu<kParseDefaultFlags>(str);
1943     }
1944     //!@}
1945 
1946     //!@name Parse from read-only string
1947     //!@{
1948 
1949     //! Parse JSON text from a read-only string (with Encoding conversion)
1950     /*! \tparam parseFlags Combination of \ref ParseFlag (must not contain \ref kParseInsituFlag).
1951         \tparam SourceEncoding Transcoding from input Encoding
1952         \param str Read-only zero-terminated string to be parsed.
1953     */
1954     template <unsigned parseFlags, typename SourceEncoding>
1955     GenericDocument& Parse(const Ch* str) {
1956         RAPIDJSON_ASSERT(!(parseFlags & kParseInsituFlag));
1957         GenericStringStream<SourceEncoding> s(str);
1958         return ParseStream<parseFlags, SourceEncoding>(s);
1959     }
1960 
1961     //! Parse JSON text from a read-only string
1962     /*! \tparam parseFlags Combination of \ref ParseFlag (must not contain \ref kParseInsituFlag).
1963         \param str Read-only zero-terminated string to be parsed.
1964     */
1965     template <unsigned parseFlags>
1966     GenericDocument& Parse(const Ch* str) {
1967         return Parse<parseFlags, Encoding>(str);
1968     }
1969 
1970     //! Parse JSON text from a read-only string (with \ref kParseDefaultFlags)
1971     /*! \param str Read-only zero-terminated string to be parsed.
1972     */
1973     GenericDocument& Parse(const Ch* str) {
1974         return Parse<kParseDefaultFlags>(str);
1975     }
1976     //!@}
1977 
1978     //!@name Handling parse errors
1979     //!@{
1980 
1981     //! Whether a parse error has occured in the last parsing.
1982     bool HasParseError() const { return parseResult_.IsError(); }
1983 
1984     //! Get the \ref ParseErrorCode of last parsing.
1985     ParseErrorCode GetParseError() const { return parseResult_.Code(); }
1986 
1987     //! Get the position of last parsing error in input, 0 otherwise.
1988     size_t GetErrorOffset() const { return parseResult_.Offset(); }
1989 
1990     //!@}
1991 
1992     //! Get the allocator of this document.
1993     Allocator& GetAllocator() {
1994         RAPIDJSON_ASSERT(allocator_);
1995         return *allocator_;
1996     }
1997 
1998     //! Get the capacity of stack in bytes.
1999     size_t GetStackCapacity() const { return stack_.GetCapacity(); }
2000 
2001 private:
2002     // clear stack on any exit from ParseStream, e.g. due to exception
2003     struct ClearStackOnExit {
2004         explicit ClearStackOnExit(GenericDocument& d) : d_(d) {}
2005         ~ClearStackOnExit() { d_.ClearStack(); }
2006     private:
2007         ClearStackOnExit(const ClearStackOnExit&);
2008         ClearStackOnExit& operator=(const ClearStackOnExit&);
2009         GenericDocument& d_;
2010     };
2011 
2012     // callers of the following private Handler functions
2013     template <typename,typename,typename> friend class GenericReader; // for parsing
2014     template <typename, typename> friend class GenericValue; // for deep copying
2015 
2016     // Implementation of Handler
2017     bool Null() { new (stack_.template Push<ValueType>()) ValueType(); return true; }
2018     bool Bool(bool b) { new (stack_.template Push<ValueType>()) ValueType(b); return true; }
2019     bool Int(int i) { new (stack_.template Push<ValueType>()) ValueType(i); return true; }
2020     bool Uint(unsigned i) { new (stack_.template Push<ValueType>()) ValueType(i); return true; }
2021     bool Int64(int64_t i) { new (stack_.template Push<ValueType>()) ValueType(i); return true; }
2022     bool Uint64(uint64_t i) { new (stack_.template Push<ValueType>()) ValueType(i); return true; }
2023     bool Double(double d) { new (stack_.template Push<ValueType>()) ValueType(d); return true; }
2024 
2025     bool String(const Ch* str, SizeType length, bool copy) {
2026         if (copy)
2027             new (stack_.template Push<ValueType>()) ValueType(str, length, GetAllocator());
2028         else
2029             new (stack_.template Push<ValueType>()) ValueType(str, length);
2030         return true;
2031     }
2032 
2033     bool StartObject() { new (stack_.template Push<ValueType>()) ValueType(kObjectType); return true; }
2034 
2035     bool Key(const Ch* str, SizeType length, bool copy) { return String(str, length, copy); }
2036 
2037     bool EndObject(SizeType memberCount) {
2038         typename ValueType::Member* members = stack_.template Pop<typename ValueType::Member>(memberCount);
2039         stack_.template Top<ValueType>()->SetObjectRaw(members, (SizeType)memberCount, GetAllocator());
2040         return true;
2041     }
2042 
2043     bool StartArray() { new (stack_.template Push<ValueType>()) ValueType(kArrayType); return true; }
2044 
2045     bool EndArray(SizeType elementCount) {
2046         ValueType* elements = stack_.template Pop<ValueType>(elementCount);
2047         stack_.template Top<ValueType>()->SetArrayRaw(elements, elementCount, GetAllocator());
2048         return true;
2049     }
2050 
2051 private:
2052     //! Prohibit copying
2053     GenericDocument(const GenericDocument&);
2054     //! Prohibit assignment
2055     GenericDocument& operator=(const GenericDocument&);
2056 
2057     void ClearStack() {
2058         if (Allocator::kNeedFree)
2059             while (stack_.GetSize() > 0)    // Here assumes all elements in stack array are GenericValue (Member is actually 2 GenericValue objects)
2060                 (stack_.template Pop<ValueType>(1))->~ValueType();
2061         else
2062             stack_.Clear();
2063         stack_.ShrinkToFit();
2064     }
2065 
2066     void Destroy() {
2067         RAPIDJSON_DELETE(ownAllocator_);
2068     }
2069 
2070     static const size_t kDefaultStackCapacity = 1024;
2071     Allocator* allocator_;
2072     Allocator* ownAllocator_;
2073     internal::Stack<StackAllocator> stack_;
2074     ParseResult parseResult_;
2075 };
2076 
2077 //! GenericDocument with UTF8 encoding
2078 typedef GenericDocument<UTF8<> > Document;
2079 
2080 // defined here due to the dependency on GenericDocument
2081 template <typename Encoding, typename Allocator>
2082 template <typename SourceAllocator>
2083 inline
2084 GenericValue<Encoding,Allocator>::GenericValue(const GenericValue<Encoding,SourceAllocator>& rhs, Allocator& allocator)
2085 {
2086     switch (rhs.GetType()) {
2087     case kObjectType:
2088     case kArrayType: { // perform deep copy via SAX Handler
2089             GenericDocument<Encoding,Allocator> d(&allocator);
2090             rhs.Accept(d);
2091             RawAssign(*d.stack_.template Pop<GenericValue>(1));
2092         }
2093         break;
2094     case kStringType:
2095         if (rhs.flags_ == kConstStringFlag) {
2096             flags_ = rhs.flags_;
2097             data_  = *reinterpret_cast<const Data*>(&rhs.data_);
2098         } else {
2099             SetStringRaw(StringRef(rhs.GetString(), rhs.GetStringLength()), allocator);
2100         }
2101         break;
2102     default: // kNumberType, kTrueType, kFalseType, kNullType
2103         flags_ = rhs.flags_;
2104         data_  = *reinterpret_cast<const Data*>(&rhs.data_);
2105     }
2106 }
2107 
2108 RAPIDJSON_NAMESPACE_END
2109 
2110 #if defined(_MSC_VER) || defined(__GNUC__)
2111 RAPIDJSON_DIAG_POP
2112 #endif
2113 
2114 #endif // RAPIDJSON_DOCUMENT_H_
2115