Add GenericArray helper class with range-based for

include/rapidjson/document.h

@@ -483,6 +483,9 @@ struct TypeHelper<ValueType, std::basic_string<typename ValueType::Ch> > {
 
 } // namespace internal
 
+template <typename ValueType>
+class GenericArray;
+
 ///////////////////////////////////////////////////////////////////////////////
 // GenericValue
 
@@ -510,6 +513,7 @@ public:
     typedef GenericValue* ValueIterator;            //!< Value iterator for iterating in array.
     typedef const GenericValue* ConstValueIterator; //!< Constant value iterator for iterating in array.
     typedef GenericValue<Encoding, Allocator> ValueType;    //!< Value type of itself.
+    typedef GenericArray<ValueType> ArrayType;
 
     //!@name Constructors and destructor.
     //@{
@@ -1556,6 +1560,9 @@ public:
         return pos;
     }
 
+    ArrayType GetArray() { RAPIDJSON_ASSERT(IsArray()); return ArrayType(*this); }
+    const ArrayType GetArray() const { RAPIDJSON_ASSERT(IsArray()); return ArrayType(*this); }
+
     //@}
 
     //!@name Number
@@ -1653,9 +1660,12 @@ public:
 
     //@}
 
+    //!@name Array
+    //@{
+
     //! Templated version for checking whether this value is type T.
     /*!
-        \tparam T Either \c bool, \c int, \c unsigned, \c int64_t, \c uint64_t, \c double, \c float, \c std::basic_string<Ch>
+        \tparam T Either \c bool, \c int, \c unsigned, \c int64_t, \c uint64_t, \c double, \c float, \c const \c char*, \c std::basic_string<Ch>
     */
     template <typename T>
     bool Is() const { return internal::TypeHelper<ValueType, T>::Is(*this); }
@@ -1669,6 +1679,8 @@ public:
     template<typename T>
     ValueType& Set(const T& data, AllocatorType& allocator) { return internal::TypeHelper<ValueType, T>::Set(*this, data, allocator); }
 
+    //@}
+
     //! Generate events of this value to a Handler.
     /*! This function adopts the GoF visitor pattern.
         Typical usage is to output this JSON value as JSON text via Writer, which is a Handler.
@@ -2278,6 +2290,65 @@ GenericValue<Encoding,Allocator>::GenericValue(const GenericValue<Encoding,Sourc
     }
 }
 
+//! Helper class for accessing Value of array type.
+/*!
+    Instance of this helper class is obtained by \c GenericValue::GetArray().
+    In addition to all APIs for array type, it provides range-based for loop if \c RAPIDJSON_HAS_CXX11_RANGE_FOR=1.
+*/
+template <typename ValueType>
+class GenericArray {
+public:
+    typedef typename ValueType::ValueIterator ValueIterator;
+    typedef typename ValueType::ConstValueIterator ConstValueIterator;
+    typedef typename ValueType::AllocatorType AllocatorType;
+    typedef typename ValueType::StringRefType StringRefType;
+
+    template <typename, typename>
+    friend class GenericValue;
+
+    GenericArray() : ptr_() {}
+    GenericArray(const GenericArray& rhs) : ptr_(rhs.ptr_) {}
+    GenericArray& operator=(GenericArray& rhs) { ptr_ = rhs.ptr_; return *this; }
+    ~GenericArray() {}
+
+    SizeType Size() const { return ptr_->Size(); }
+    SizeType Capacity() const { return ptr_->Capacity(); }
+    bool Empty() const { return ptr_->Empty(); }
+    void Clear() { ptr_->Clear(); }
+    ValueType& operator[](SizeType index) { return (*ptr_)[index]; }
+    const ValueType& operator[](SizeType index) const {  return (*ptr_)[index]; }
+    ValueIterator Begin() { return ptr_->Begin(); }
+    ValueIterator End() { return ptr_->End(); }
+    ConstValueIterator Begin() const { return ptr_->Begin(); }
+    ConstValueIterator End() const { return ptr_->End(); }
+    GenericArray& Reserve(SizeType newCapacity, AllocatorType &allocator) { ptr_->Reserve(newCapacity, allocator); return *this; }
+    GenericArray& PushBack(ValueType& value, AllocatorType& allocator) { ptr_->PushBack(value, allocator); return *this; }
+#if RAPIDJSON_HAS_CXX11_RVALUE_REFS
+    GenericArray& PushBack(ValueType&& value, AllocatorType& allocator) { ptr_->PushBack(value, allocator); return *this; }
+#endif // RAPIDJSON_HAS_CXX11_RVALUE_REFS
+    GenericArray& PushBack(StringRefType value, AllocatorType& allocator) { ptr_->PushBack(value, allocator); return *this; }
+    template <typename T>
+    RAPIDJSON_DISABLEIF_RETURN((internal::OrExpr<internal::IsPointer<T>, internal::IsGenericValue<T> >), (GenericArray&))
+    PushBack(T value, AllocatorType& allocator) { ptr_->PushBack(value, allocator); return *this; }
+    GenericArray& PopBack() { ptr_->PopBack(); return *this; }
+    ValueIterator Erase(ConstValueIterator pos) { return ptr_->Erase(pos); }
+    ValueIterator Erase(ConstValueIterator first, ConstValueIterator last) { return ptr_->Erase(first, last); }
+
+#if RAPIDJSON_HAS_CXX11_RANGE_FOR
+    ValueIterator begin() { return ptr_->Begin(); }
+    ValueIterator end() { return ptr_->End(); }
+    ConstValueIterator begin() const { return ptr_->Begin(); }
+    ConstValueIterator end() const { return ptr_->End(); }
+#endif
+
+private:
+    GenericArray(ValueType& value) : ptr_(&value) {}
+    GenericArray(const ValueType& value) : ptr_(const_cast<ValueType*>(&value)) {}
+    ValueType* ptr_;
+};
+
+typedef GenericArray<Value> Array;
+
 RAPIDJSON_NAMESPACE_END
 
 #ifdef _MSC_VER

include/rapidjson/rapidjson.h

@@ -530,6 +530,17 @@ RAPIDJSON_NAMESPACE_END
 #define RAPIDJSON_HAS_CXX11_TYPETRAITS 0
 #endif
 
+#ifndef RAPIDJSON_HAS_CXX11_RANGE_FOR
+#if defined(__clang)
+#define RAPIDJSON_HAS_CXX11_RANGE_FOR __has_feature(cxx_range_for)
+#elif (defined(RAPIDJSON_GNUC) && (RAPIDJSON_GNUC >= RAPIDJSON_VERSION_CODE(4,3,0)) && defined(__GXX_EXPERIMENTAL_CXX0X__)) || \
+      (defined(_MSC_VER) && _MSC_VER >= 1600)
+#define RAPIDJSON_HAS_CXX11_RANGE_FOR 1
+#else
+#define RAPIDJSON_HAS_CXX11_RANGE_FOR 0
+#endif
+#endif // RAPIDJSON_HAS_CXX11_RANGE_FOR
+
 //!@endcond
 
 ///////////////////////////////////////////////////////////////////////////////

test/unittest/valuetest.cpp

@@ -824,25 +824,9 @@ TEST(Value, SetStringNullException) {
     EXPECT_THROW(v.SetString(0, 0), AssertException);
 }
 
-TEST(Value, Array) {
-    Value x(kArrayType);
-    const Value& y = x;
-    Value::AllocatorType allocator;
-
-    EXPECT_EQ(kArrayType, x.GetType());
-    EXPECT_TRUE(x.IsArray());
-    EXPECT_TRUE(x.Empty());
-    EXPECT_EQ(0u, x.Size());
-    EXPECT_TRUE(y.IsArray());
-    EXPECT_TRUE(y.Empty());
-    EXPECT_EQ(0u, y.Size());
-
-    EXPECT_FALSE(x.IsNull());
-    EXPECT_FALSE(x.IsBool());
-    EXPECT_FALSE(x.IsFalse());
-    EXPECT_FALSE(x.IsTrue());
-    EXPECT_FALSE(x.IsString());
-    EXPECT_FALSE(x.IsObject());
+template <typename T, typename Allocator>
+void TestArray(T& x, Allocator& allocator) {
+    const T& y = x;
 
     // PushBack()
     Value v;
@@ -889,7 +873,7 @@ TEST(Value, Array) {
 #endif
 
     // iterator
-    Value::ValueIterator itr = x.Begin();
+    typename T::ValueIterator itr = x.Begin();
     EXPECT_TRUE(itr != x.End());
     EXPECT_TRUE(itr->IsNull());
     ++itr;
@@ -908,7 +892,7 @@ TEST(Value, Array) {
     EXPECT_STREQ("foo", itr->GetString());
 
     // const iterator
-    Value::ConstValueIterator citr = y.Begin();
+    typename T::ConstValueIterator citr = y.Begin();
     EXPECT_TRUE(citr != y.End());
     EXPECT_TRUE(citr->IsNull());
     ++citr;
@@ -994,6 +978,29 @@ TEST(Value, Array) {
                 EXPECT_EQ(i + removeCount, x[static_cast<SizeType>(i)][0].GetUint());
         }
     }
+}
+
+TEST(Value, Array) {
+    Value x(kArrayType);
+    const Value& y = x;
+    Value::AllocatorType allocator;
+
+    EXPECT_EQ(kArrayType, x.GetType());
+    EXPECT_TRUE(x.IsArray());
+    EXPECT_TRUE(x.Empty());
+    EXPECT_EQ(0u, x.Size());
+    EXPECT_TRUE(y.IsArray());
+    EXPECT_TRUE(y.Empty());
+    EXPECT_EQ(0u, y.Size());
+
+    EXPECT_FALSE(x.IsNull());
+    EXPECT_FALSE(x.IsBool());
+    EXPECT_FALSE(x.IsFalse());
+    EXPECT_FALSE(x.IsTrue());
+    EXPECT_FALSE(x.IsString());
+    EXPECT_FALSE(x.IsObject());
+
+    TestArray(x, allocator);
 
     // Working in gcc without C++11, but VS2013 cannot compile. To be diagnosed.
     // http://en.wikipedia.org/wiki/Erase-remove_idiom
@@ -1017,6 +1024,52 @@ TEST(Value, Array) {
     EXPECT_TRUE(z.Empty());
 }
 
+TEST(Value, ArrayHelper) {
+    Value::AllocatorType allocator;
+    {
+        Value x(kArrayType);
+        Array a = x.GetArray();
+        TestArray(a, allocator);
+    }
+
+    Value x(kArrayType);
+    Array a = x.GetArray();
+    a.PushBack(1, allocator);
+
+    Array a2(a); // copy constructor
+    EXPECT_EQ(1, a2.Size());
+
+    Array a3;   // default constructor
+    a3 = a;     // assignment operator
+    EXPECT_EQ(1, a3.Size());    
+}
+
+#if RAPIDJSON_HAS_CXX11_RANGE_FOR
+TEST(Value, ArrayHelperRangeFor) {
+    Value::AllocatorType allocator;
+    Value x(kArrayType);
+
+    for (int i = 0; i < 10; i++)
+        x.PushBack(i, allocator);
+
+    {
+        int i = 0;
+        for (auto& v : x.GetArray())
+            EXPECT_EQ(i++, v.GetInt());
+        EXPECT_EQ(i, 10);
+    }
+    {
+        int i = 0;
+        for (auto& v : const_cast<const Value&>(x).GetArray())
+            EXPECT_EQ(i++, v.GetInt());
+        EXPECT_EQ(i, 10);
+    }
+
+    // Array a = x.GetArray();
+    // Array ca = const_cast<const Value&>(x).GetArray();
+}
+#endif
+
 TEST(Value, Object) {
     Value x(kObjectType);
     const Value& y = x; // const version