Add XXXByPointer() helper functions

include/rapidjson/document.h

@@ -427,6 +427,7 @@ public:
     typedef typename GenericMemberIterator<true,Encoding,Allocator>::Iterator ConstMemberIterator;  //!< Constant member iterator for iterating in object.
     typedef GenericValue* ValueIterator;            //!< Value iterator for iterating in array.
     typedef const GenericValue* ConstValueIterator; //!< Constant value iterator for iterating in array.
+    typedef GenericValue<Encoding, Allocator> ValueType;    //!< Value type of itself.
 
     //!@name Constructors and destructor.
     //@{
@@ -1661,7 +1662,6 @@ template <typename Encoding, typename Allocator = MemoryPoolAllocator<>, typenam
 class GenericDocument : public GenericValue<Encoding, Allocator> {
 public:
     typedef typename Encoding::Ch Ch;                       //!< Character type derived from Encoding.
-    typedef GenericValue<Encoding, Allocator> ValueType;    //!< Value type of the document.
     typedef Allocator AllocatorType;                        //!< Allocator type from template parameter.
 
     //! Constructor

include/rapidjson/pointer.h

@@ -325,6 +325,72 @@ private:
     bool valid_;
 };
 
+template <typename T>
+typename T::ValueType& CreateValueByPointer(T& root, const GenericPointer<typename T::ValueType>& pointer, typename T::AllocatorType& a) {
+    return pointer.Create(root, a);
+}
+
+template <typename T, typename CharType, size_t N>
+typename T::ValueType& CreateValueByPointer(T& root, const CharType(&source)[N], typename T::AllocatorType& a) {
+    const Pointer pointer(source, N - 1);
+    return pointer.Create(root, a);
+}
+
+template <typename T>
+typename T::ValueType* GetValueByPointer(T& root, const GenericPointer<typename T::ValueType>& pointer) {
+    return pointer.Get(root);
+}
+
+template <typename T>
+const typename T::ValueType* GetValueByPointer(const T& root, const GenericPointer<typename T::ValueType>& pointer) {
+    return pointer.Get(root);
+}
+
+template <typename T, typename CharType, size_t N>
+typename T::ValueType* GetValueByPointer(T& root, const CharType (&source)[N]) {
+    const Pointer pointer(source, N - 1);
+    return pointer.Get(root);
+}
+
+template <typename T, typename CharType, size_t N>
+const typename T::ValueType* GetValueByPointer(const T& root, const CharType(&source)[N]) {
+    const Pointer pointer(source, N - 1);
+    return pointer.Get(root);
+}
+
+template <typename T>
+typename T::ValueType& GetValueByPointerWithDefault(T& root, const GenericPointer<typename T::ValueType>& pointer, const typename T::ValueType& defaultValue, typename T::AllocatorType& a) {
+    return pointer.GetWithDefault(root, defaultValue, a);
+}
+
+template <typename T, typename CharType, size_t N>
+typename T::ValueType& GetValueByPointerWithDefault(T& root, const CharType(&source)[N], const typename T::ValueType& defaultValue, typename T::AllocatorType& a) {
+    const Pointer pointer(source, N - 1);
+    return pointer.GetWithDefault(root, defaultValue, a);
+}
+
+template <typename T>
+typename T::ValueType& SetValueByPointer(T& root, const GenericPointer<typename T::ValueType>& pointer, typename T::ValueType& value, typename T::AllocatorType& a) {
+    return pointer.Set(root, value, a);
+}
+
+template <typename T, typename CharType, size_t N>
+typename T::ValueType& SetValueByPointer(T& root, const CharType(&source)[N], typename T::ValueType& value, typename T::AllocatorType& a) {
+    const Pointer pointer(source, N - 1);
+    return pointer.Set(root, value , a);
+}
+
+template <typename T>
+typename T::ValueType& SwapValueByPointer(T& root, const GenericPointer<typename T::ValueType>& pointer, typename T::ValueType& value, typename T::AllocatorType& a) {
+    return pointer.Swap(root, value, a);
+}
+
+template <typename T, typename CharType, size_t N>
+typename T::ValueType& SwapValueByPointer(T& root, const CharType(&source)[N], typename T::ValueType& value, typename T::AllocatorType& a) {
+    const Pointer pointer(source, N - 1);
+    return pointer.Swap(root, value, a);
+}
+
 typedef GenericPointer<Value> Pointer;
 
 RAPIDJSON_NAMESPACE_END

test/unittest/pointertest.cpp

@@ -244,9 +244,18 @@ TEST(Pointer, Assignment) {
 
 TEST(Pointer, Create) {
     Document d;
-    EXPECT_EQ(&d, &Pointer("").Create(d, d.GetAllocator()));
-    EXPECT_EQ(&d["foo"], &Pointer("/foo").Create(d, d.GetAllocator()));
-    EXPECT_EQ(&d["foo"][0], &Pointer("/foo/0").Create(d, d.GetAllocator()));
+    {
+        Value* v = &Pointer("").Create(d, d.GetAllocator());
+        EXPECT_EQ(&d, v);
+    }
+    {
+        Value* v = &Pointer("/foo").Create(d, d.GetAllocator());
+        EXPECT_EQ(&d["foo"], v);
+    }
+    {
+        Value* v = &Pointer("/foo/0").Create(d, d.GetAllocator());
+        EXPECT_EQ(&d["foo"][0], v);
+    }
 }
 
 TEST(Pointer, Get) {
@@ -265,6 +274,7 @@ TEST(Pointer, Get) {
     EXPECT_EQ(&d["k\"l"], Pointer("/k\"l").Get(d));
     EXPECT_EQ(&d[" "], Pointer("/ ").Get(d));
     EXPECT_EQ(&d["m~n"], Pointer("/m~0n").Get(d));
+    EXPECT_TRUE(Pointer("/abc").Get(d) == 0);
 }
 
 TEST(Pointer, GetWithDefault) {
@@ -298,3 +308,65 @@ TEST(Pointer, Swap) {
     EXPECT_STREQ("baz", d["foo"][0].GetString());
     EXPECT_STREQ("bar", d["foo"][1].GetString());
 }
+
+TEST(Pointer, CreateValueByPointer) {
+    Document d;
+    Document::AllocatorType& a = d.GetAllocator();
+
+    {
+        Value& v = CreateValueByPointer(d, Pointer("/foo/0"), a);
+        EXPECT_EQ(&d["foo"][0], &v);
+    }
+    {
+        Value& v = CreateValueByPointer(d, "/foo/1", a);
+        EXPECT_EQ(&d["foo"][1], &v);
+    }
+}
+
+TEST(Pointer, GetValueByPointer) {
+    Document d;
+    d.Parse(kJson);
+
+    EXPECT_EQ(&d["foo"][0], GetValueByPointer(d, Pointer("/foo/0")));
+    EXPECT_EQ(&d["foo"][0], GetValueByPointer(d, "/foo/0"));
+
+    // const version
+    const Value& v = d;
+    EXPECT_EQ(&d["foo"][0], GetValueByPointer(v, Pointer("/foo/0")));
+    EXPECT_EQ(&d["foo"][0], GetValueByPointer(v, "/foo/0"));
+}
+
+TEST(Pointer, GetValueByPointerWithDefault) {
+    Document d;
+    d.Parse(kJson);
+
+    Document::AllocatorType& a = d.GetAllocator();
+    const Value v("qux");
+    EXPECT_TRUE(Value("bar") == GetValueByPointerWithDefault(d, Pointer("/foo/0"), v, a));
+    EXPECT_TRUE(Value("baz") == GetValueByPointerWithDefault(d, "/foo/1", v, a));
+}
+
+TEST(Pointer, SetValueByPointer) {
+    Document d;
+    d.Parse(kJson);
+    Document::AllocatorType& a = d.GetAllocator();
+
+    SetValueByPointer(d, Pointer("/foo/0"), Value(123).Move(), a);
+    EXPECT_EQ(123, d["foo"][0].GetInt());
+
+    SetValueByPointer(d, "/foo/2", Value(456).Move(), a);
+    EXPECT_EQ(456, d["foo"][2].GetInt());
+}
+
+TEST(Pointer, SwapValueByPointer) {
+    Document d;
+    d.Parse(kJson);
+    Document::AllocatorType& a = d.GetAllocator();
+    SwapValueByPointer(d, Pointer("/foo/0"), *GetValueByPointer(d, "/foo/1"), a);
+    EXPECT_STREQ("baz", d["foo"][0].GetString());
+    EXPECT_STREQ("bar", d["foo"][1].GetString());
+
+    SwapValueByPointer(d, "/foo/0", *GetValueByPointer(d, "/foo/1"), a);
+    EXPECT_STREQ("bar", d["foo"][0].GetString());
+    EXPECT_STREQ("baz", d["foo"][1].GetString());
+}