add movable insert method.

Author: dota17

include/json/value.h

@@ -465,7 +465,11 @@ Json::Value obj_value(Json::objectValue); // {}
   Value& append(const Value& value);
   /// \brief Insert value in array at specific index
   bool insert(ArrayIndex index, const Value& newValue);
+#if JSON_HAS_RVALUE_REFERENCES
   Value& append(Value&& value);
+  bool insert(ArrayIndex index, const Value&& newValue);
+#endif
+
   /// Access an object value by name, create a null member if it does not exist.
   /// \note Because of our implementation, keys are limited to 2^30 -1 chars.
   ///  Exceeding that will cause an exception.

src/lib_json/json_value.cpp

@@ -1175,7 +1175,7 @@ bool Value::insert(ArrayIndex index, const Value& newValue){
   if(type() != arrayValue){
     return false;
   }
-  if(!isValidIndex()){
+  if(!isValidIndex(index)){
     return false;
   }
   ArrayIndex oldsize = size();
@@ -1190,10 +1190,28 @@ bool Value::insert(ArrayIndex index, const Value& newValue){
   (*this)[index]= newValue;
   return true;
 }
-Value& Value::append(Value&& value) {
-  return (*this)[size()] = std::move(value);
+#if JSON_HAS_RVALUE_REFERENCES
+Value& Value::append(Value&& value) { return (*this)[size()] = std::move(value); }
+bool Value::insert(ArrayIndex index, const Value&& newValue){
+  if(type() != arrayValue){
+    return false;
+  }
+  if(!isValidIndex(index)){
+    return false;
+  }
+  ArrayIndex oldsize = size();
+  resize(oldsize+1);
+  ArrayIndex length = size();
+  if(length != oldsize +1){
+    return false;
+  }
+  for(ArrayIndex i = length ; i> index ; i--){
+    (*this)[i] = (*this)[i-1];
+  }
+  (*this)[index]= std::move(newValue);
+  return true;
 }
-
+#endif
 Value Value::get(char const* begin,
                  char const* end,
                  Value const& defaultValue) const {

src/test_lib_json/main.cpp

@@ -308,16 +308,18 @@ JSONTEST_FIXTURE(ValueTest, arrayIssue252) {
   // JSONTEST_ASSERT_EQUAL(5, root["array"].size());
 }
 JSONTEST_FIXTURE(ValueTest, arrayIssue691) {
-  Json::Value array2_;
-  array2_.append(1);
-  array2_.append(2);
-  array2_.append(3);
-  array2_.append(5);
-  ////use insert method
-  array2_.insert(3,4);
-  JSONTEST_ASSERT_EQUAL(Json::Value(3),array2_[2]);
-  JSONTEST_ASSERT_EQUAL(Json::Value(4),array2_[3]);
-  JSONTEST_ASSERT_EQUAL(Json::Value(5),array2_[4]);    
+  Json::Value array2;
+  array2.append(10);  // index 0
+  array2.append(20);  // index 1
+  array2.append(30);  // index 2
+  array2.append(50);  // index 3
+
+  JSONTEST_ASSERT_EQUAL(Json::Value(50),array2[3]);
+
+  array2.insert(3,40); // index 3
+  // After updating, index 3 should be changed from 50 to 40, and 50 moved to index 4.
+  JSONTEST_ASSERT_EQUAL(Json::Value(40),array2[3]);
+  JSONTEST_ASSERT_EQUAL(Json::Value(50),array2[4]);    
 }
 JSONTEST_FIXTURE(ValueTest, null) {
   JSONTEST_ASSERT_EQUAL(Json::nullValue, null_.type());