add a new method to insert a new value in an array at specific index.

Author: dota17

include/json/value.h

@@ -463,8 +463,9 @@ Json::Value obj_value(Json::objectValue); // {}
   ///
   /// Equivalent to jsonvalue[jsonvalue.size()] = value;
   Value& append(const Value& value);
+  /// \brief Insert value in array at specific index
+  bool insert(ArrayIndex index, const Value& newValue);
   Value& append(Value&& value);
-
   /// 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

@@ -1170,7 +1170,26 @@ Value const& Value::operator[](CppTL::ConstString const& key) const {
 #endif
 
 Value& Value::append(const Value& value) { return (*this)[size()] = value; }
-
+/// \brief Insert value in array at specific index
+bool Value::insert(ArrayIndex index, const Value& newValue){
+  if(type() != arrayValue){
+    return false;
+  }
+  if(!isValidIndex()){
+    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]= newValue;
+  return true;
+}
 Value& Value::append(Value&& value) {
   return (*this)[size()] = std::move(value);
 }

src/test_lib_json/main.cpp

@@ -307,7 +307,18 @@ 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]);    
+}
 JSONTEST_FIXTURE(ValueTest, null) {
   JSONTEST_ASSERT_EQUAL(Json::nullValue, null_.type());
 
@@ -2535,6 +2546,7 @@ int main(int argc, const char* argv[]) {
   JSONTEST_REGISTER_FIXTURE(runner, ValueTest, objects);
   JSONTEST_REGISTER_FIXTURE(runner, ValueTest, arrays);
   JSONTEST_REGISTER_FIXTURE(runner, ValueTest, arrayIssue252);
+  JSONTEST_REGISTER_FIXTURE(runner, ValueTest, arrayIssue691);
   JSONTEST_REGISTER_FIXTURE(runner, ValueTest, null);
   JSONTEST_REGISTER_FIXTURE(runner, ValueTest, strings);
   JSONTEST_REGISTER_FIXTURE(runner, ValueTest, bools);