diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-ec2-protocol/include/aws/ec2-protocol/model/RecursiveXmlShapesOutputNested1.h b/generated/protocol-tests/test-clients/aws-cpp-sdk-ec2-protocol/include/aws/ec2-protocol/model/RecursiveXmlShapesOutputNested1.h
index 5b3b3aea6e0..1428be1bcc0 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-ec2-protocol/include/aws/ec2-protocol/model/RecursiveXmlShapesOutputNested1.h
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-ec2-protocol/include/aws/ec2-protocol/model/RecursiveXmlShapesOutputNested1.h
@@ -23,6 +23,7 @@ namespace EC2Protocol
 {
 namespace Model
 {
+  class RecursiveXmlShapesOutputNested2;
 
   class RecursiveXmlShapesOutputNested1
   {
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-ec2-protocol/include/aws/ec2-protocol/model/RecursiveXmlShapesOutputNested2.h b/generated/protocol-tests/test-clients/aws-cpp-sdk-ec2-protocol/include/aws/ec2-protocol/model/RecursiveXmlShapesOutputNested2.h
index 535d13f8359..7532421c47c 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-ec2-protocol/include/aws/ec2-protocol/model/RecursiveXmlShapesOutputNested2.h
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-ec2-protocol/include/aws/ec2-protocol/model/RecursiveXmlShapesOutputNested2.h
@@ -23,6 +23,7 @@ namespace EC2Protocol
 {
 namespace Model
 {
+  class RecursiveXmlShapesOutputNested1;
 
   class RecursiveXmlShapesOutputNested2
   {
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-ec2-protocol/source/model/XmlTimestampsResponse.cpp b/generated/protocol-tests/test-clients/aws-cpp-sdk-ec2-protocol/source/model/XmlTimestampsResponse.cpp
index 9f92ad0aec3..41f0229a547 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-ec2-protocol/source/model/XmlTimestampsResponse.cpp
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-ec2-protocol/source/model/XmlTimestampsResponse.cpp
@@ -56,12 +56,12 @@ XmlTimestampsResponse& XmlTimestampsResponse::operator =(const Aws::AmazonWebSer
     XmlNode epochSecondsNode = resultNode.FirstChild("epochSeconds");
     if(!epochSecondsNode.IsNull())
     {
-      m_epochSeconds = DateTime(StringUtils::Trim(Aws::Utils::Xml::DecodeEscapedXmlText(epochSecondsNode.GetText()).c_str()).c_str(), Aws::Utils::DateFormat::$CppViewHelper.computeTimestampFormatInXml($member.shape));
+      m_epochSeconds = DateTime(StringUtils::ConvertToDouble(StringUtils::Trim(Aws::Utils::Xml::DecodeEscapedXmlText(epochSecondsNode.GetText()).c_str()).c_str()));
     }
     XmlNode epochSecondsOnTargetNode = resultNode.FirstChild("epochSecondsOnTarget");
     if(!epochSecondsOnTargetNode.IsNull())
     {
-      m_epochSecondsOnTarget = DateTime(StringUtils::Trim(Aws::Utils::Xml::DecodeEscapedXmlText(epochSecondsOnTargetNode.GetText()).c_str()).c_str(), Aws::Utils::DateFormat::$CppViewHelper.computeTimestampFormatInXml($member.shape));
+      m_epochSecondsOnTarget = DateTime(StringUtils::ConvertToDouble(StringUtils::Trim(Aws::Utils::Xml::DecodeEscapedXmlText(epochSecondsOnTargetNode.GetText()).c_str()).c_str()));
     }
     XmlNode httpDateNode = resultNode.FirstChild("httpDate");
     if(!httpDateNode.IsNull())
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-query-protocol/include/aws/query-protocol/model/RecursiveXmlShapesOutputNested1.h b/generated/protocol-tests/test-clients/aws-cpp-sdk-query-protocol/include/aws/query-protocol/model/RecursiveXmlShapesOutputNested1.h
index fd9b4b4e5c5..73ec802fe85 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-query-protocol/include/aws/query-protocol/model/RecursiveXmlShapesOutputNested1.h
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-query-protocol/include/aws/query-protocol/model/RecursiveXmlShapesOutputNested1.h
@@ -23,6 +23,7 @@ namespace QueryProtocol
 {
 namespace Model
 {
+  class RecursiveXmlShapesOutputNested2;
 
   class RecursiveXmlShapesOutputNested1
   {
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-query-protocol/include/aws/query-protocol/model/RecursiveXmlShapesOutputNested2.h b/generated/protocol-tests/test-clients/aws-cpp-sdk-query-protocol/include/aws/query-protocol/model/RecursiveXmlShapesOutputNested2.h
index d2368ae7904..4a57f21a23a 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-query-protocol/include/aws/query-protocol/model/RecursiveXmlShapesOutputNested2.h
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-query-protocol/include/aws/query-protocol/model/RecursiveXmlShapesOutputNested2.h
@@ -23,6 +23,7 @@ namespace QueryProtocol
 {
 namespace Model
 {
+  class RecursiveXmlShapesOutputNested1;
 
   class RecursiveXmlShapesOutputNested2
   {
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-query-protocol/source/model/XmlTimestampsResult.cpp b/generated/protocol-tests/test-clients/aws-cpp-sdk-query-protocol/source/model/XmlTimestampsResult.cpp
index 920f0fb2b19..c3e430fc828 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-query-protocol/source/model/XmlTimestampsResult.cpp
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-query-protocol/source/model/XmlTimestampsResult.cpp
@@ -56,12 +56,12 @@ XmlTimestampsResult& XmlTimestampsResult::operator =(const Aws::AmazonWebService
     XmlNode epochSecondsNode = resultNode.FirstChild("epochSeconds");
     if(!epochSecondsNode.IsNull())
     {
-      m_epochSeconds = DateTime(StringUtils::Trim(Aws::Utils::Xml::DecodeEscapedXmlText(epochSecondsNode.GetText()).c_str()).c_str(), Aws::Utils::DateFormat::$CppViewHelper.computeTimestampFormatInXml($member.shape));
+      m_epochSeconds = DateTime(StringUtils::ConvertToDouble(StringUtils::Trim(Aws::Utils::Xml::DecodeEscapedXmlText(epochSecondsNode.GetText()).c_str()).c_str()));
     }
     XmlNode epochSecondsOnTargetNode = resultNode.FirstChild("epochSecondsOnTarget");
     if(!epochSecondsOnTargetNode.IsNull())
     {
-      m_epochSecondsOnTarget = DateTime(StringUtils::Trim(Aws::Utils::Xml::DecodeEscapedXmlText(epochSecondsOnTargetNode.GetText()).c_str()).c_str(), Aws::Utils::DateFormat::$CppViewHelper.computeTimestampFormatInXml($member.shape));
+      m_epochSecondsOnTarget = DateTime(StringUtils::ConvertToDouble(StringUtils::Trim(Aws::Utils::Xml::DecodeEscapedXmlText(epochSecondsOnTargetNode.GetText()).c_str()).c_str()));
     }
     XmlNode httpDateNode = resultNode.FirstChild("httpDate");
     if(!httpDateNode.IsNull())
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/include/aws/rest-xml-protocol/model/RecursiveShapesInputOutputNested1.h b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/include/aws/rest-xml-protocol/model/RecursiveShapesInputOutputNested1.h
index 27fa2cbc13d..ad2379c00d0 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/include/aws/rest-xml-protocol/model/RecursiveShapesInputOutputNested1.h
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/include/aws/rest-xml-protocol/model/RecursiveShapesInputOutputNested1.h
@@ -22,6 +22,7 @@ namespace RestXmlProtocol
 {
 namespace Model
 {
+  class RecursiveShapesInputOutputNested2;
 
   class RecursiveShapesInputOutputNested1
   {
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/include/aws/rest-xml-protocol/model/RecursiveShapesInputOutputNested2.h b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/include/aws/rest-xml-protocol/model/RecursiveShapesInputOutputNested2.h
index 6e598a90cb0..f2343018a30 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/include/aws/rest-xml-protocol/model/RecursiveShapesInputOutputNested2.h
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/include/aws/rest-xml-protocol/model/RecursiveShapesInputOutputNested2.h
@@ -22,6 +22,7 @@ namespace RestXmlProtocol
 {
 namespace Model
 {
+  class RecursiveShapesInputOutputNested1;
 
   class RecursiveShapesInputOutputNested2
   {
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/FlattenedXmlMapRequest.cpp b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/FlattenedXmlMapRequest.cpp
index f949055fdba..4ad78561e33 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/FlattenedXmlMapRequest.cpp
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/FlattenedXmlMapRequest.cpp
@@ -28,6 +28,15 @@ Aws::String FlattenedXmlMapRequest::SerializePayload() const
   Aws::StringStream ss;
   if(m_myMapHasBeenSet)
   {
+   XmlNode myMapParentNode = parentNode.CreateChildElement("myMap");
+   for(const auto& mapItem : m_myMap)
+   {
+     XmlNode myMapMapEntryNode = myMapParentNode.CreateChildElement("entry");
+     XmlNode myMapKeyNode = myMapMapEntryNode.CreateChildElement("key");
+     myMapKeyNode.SetText(mapItem.first);
+     XmlNode myMapValueNode = myMapMapEntryNode.CreateChildElement("value");
+     myMapValueNode.SetText(FooEnumMapper::GetNameForFooEnum(mapItem.second));
+   }
   }
 
   return payloadDoc.ConvertToString();
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/FlattenedXmlMapWithXmlNameRequest.cpp b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/FlattenedXmlMapWithXmlNameRequest.cpp
index 610458f1742..3f72be89a46 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/FlattenedXmlMapWithXmlNameRequest.cpp
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/FlattenedXmlMapWithXmlNameRequest.cpp
@@ -28,6 +28,15 @@ Aws::String FlattenedXmlMapWithXmlNameRequest::SerializePayload() const
   Aws::StringStream ss;
   if(m_myMapHasBeenSet)
   {
+   XmlNode myMapParentNode = parentNode.CreateChildElement("KVP");
+   for(const auto& mapItem : m_myMap)
+   {
+     XmlNode myMapMapEntryNode = myMapParentNode.CreateChildElement("KVP");
+     XmlNode myMapKeyNode = myMapMapEntryNode.CreateChildElement("K");
+     myMapKeyNode.SetText(mapItem.first);
+     XmlNode myMapValueNode = myMapMapEntryNode.CreateChildElement("V");
+     myMapValueNode.SetText(mapItem.second);
+   }
   }
 
   return payloadDoc.ConvertToString();
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/NestedXmlMapWithXmlNameRequest.cpp b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/NestedXmlMapWithXmlNameRequest.cpp
index 9a9551ed1c1..a070835c1a6 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/NestedXmlMapWithXmlNameRequest.cpp
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/NestedXmlMapWithXmlNameRequest.cpp
@@ -30,6 +30,15 @@ Aws::String NestedXmlMapWithXmlNameRequest::SerializePayload() const
   Aws::StringStream ss;
   if(m_nestedXmlMapWithXmlNameMapHasBeenSet)
   {
+   XmlNode nestedXmlMapWithXmlNameMapParentNode = parentNode.CreateChildElement("nestedXmlMapWithXmlNameMap");
+   for(const auto& mapItem : m_nestedXmlMapWithXmlNameMap)
+   {
+     XmlNode nestedXmlMapWithXmlNameMapMapEntryNode = nestedXmlMapWithXmlNameMapParentNode.CreateChildElement("entry");
+     XmlNode nestedXmlMapWithXmlNameMapKeyNode = nestedXmlMapWithXmlNameMapMapEntryNode.CreateChildElement("OuterKey");
+     nestedXmlMapWithXmlNameMapKeyNode.SetText(mapItem.first);
+     XmlNode nestedXmlMapWithXmlNameMapValueNode = nestedXmlMapWithXmlNameMapMapEntryNode.CreateChildElement("value");
+     nestedXmlMapWithXmlNameMapValueNode.SetText(mapItem.second);
+   }
   }
 
   return payloadDoc.ConvertToString();
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/NestedXmlMapsRequest.cpp b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/NestedXmlMapsRequest.cpp
index 5db9179dbaa..eabb318e0c5 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/NestedXmlMapsRequest.cpp
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/NestedXmlMapsRequest.cpp
@@ -29,10 +29,28 @@ Aws::String NestedXmlMapsRequest::SerializePayload() const
   Aws::StringStream ss;
   if(m_nestedMapHasBeenSet)
   {
+   XmlNode nestedMapParentNode = parentNode.CreateChildElement("nestedMap");
+   for(const auto& mapItem : m_nestedMap)
+   {
+     XmlNode nestedMapMapEntryNode = nestedMapParentNode.CreateChildElement("entry");
+     XmlNode nestedMapKeyNode = nestedMapMapEntryNode.CreateChildElement("key");
+     nestedMapKeyNode.SetText(mapItem.first);
+     XmlNode nestedMapValueNode = nestedMapMapEntryNode.CreateChildElement("value");
+     nestedMapValueNode.SetText(mapItem.second);
+   }
   }
 
   if(m_flatNestedMapHasBeenSet)
   {
+   XmlNode flatNestedMapParentNode = parentNode.CreateChildElement("flatNestedMap");
+   for(const auto& mapItem : m_flatNestedMap)
+   {
+     XmlNode flatNestedMapMapEntryNode = flatNestedMapParentNode.CreateChildElement("entry");
+     XmlNode flatNestedMapKeyNode = flatNestedMapMapEntryNode.CreateChildElement("key");
+     flatNestedMapKeyNode.SetText(mapItem.first);
+     XmlNode flatNestedMapValueNode = flatNestedMapMapEntryNode.CreateChildElement("value");
+     flatNestedMapValueNode.SetText(mapItem.second);
+   }
   }
 
   return payloadDoc.ConvertToString();
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlEmptyListsRequest.cpp b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlEmptyListsRequest.cpp
index 60f021cfe97..c5765ecfb5a 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlEmptyListsRequest.cpp
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlEmptyListsRequest.cpp
@@ -90,7 +90,7 @@ Aws::String XmlEmptyListsRequest::SerializePayload() const
    for(const auto& item : m_timestampList)
    {
      XmlNode timestampListNode = timestampListParentNode.CreateChildElement("Timestamp");
-     timestampListNode.SetText(item.ToGmtString(Aws::Utils::DateFormat::ISO_8601);
+     timestampListNode.SetText(item.ToGmtString(Aws::Utils::DateFormat::ISO_8601));
    }
   }
 
@@ -122,6 +122,7 @@ Aws::String XmlEmptyListsRequest::SerializePayload() const
    for(const auto& item : m_nestedStringList)
    {
      XmlNode nestedStringListNode = nestedStringListParentNode.CreateChildElement("StringList");
+     nestedStringListNode.SetText(item);
    }
   }
 
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlEmptyMapsRequest.cpp b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlEmptyMapsRequest.cpp
index c87161849ab..f848e6c39d9 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlEmptyMapsRequest.cpp
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlEmptyMapsRequest.cpp
@@ -28,6 +28,15 @@ Aws::String XmlEmptyMapsRequest::SerializePayload() const
   Aws::StringStream ss;
   if(m_myMapHasBeenSet)
   {
+   XmlNode myMapParentNode = parentNode.CreateChildElement("myMap");
+   for(const auto& mapItem : m_myMap)
+   {
+     XmlNode myMapMapEntryNode = myMapParentNode.CreateChildElement("entry");
+     XmlNode myMapKeyNode = myMapMapEntryNode.CreateChildElement("key");
+     myMapKeyNode.SetText(mapItem.first);
+     XmlNode myMapValueNode = myMapMapEntryNode.CreateChildElement("value");
+     mapItem.second.AddToNode(myMapValueNode);
+   }
   }
 
   return payloadDoc.ConvertToString();
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlEnumsRequest.cpp b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlEnumsRequest.cpp
index b563ff0dde5..85a003fc008 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlEnumsRequest.cpp
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlEnumsRequest.cpp
@@ -74,6 +74,15 @@ Aws::String XmlEnumsRequest::SerializePayload() const
 
   if(m_fooEnumMapHasBeenSet)
   {
+   XmlNode fooEnumMapParentNode = parentNode.CreateChildElement("fooEnumMap");
+   for(const auto& mapItem : m_fooEnumMap)
+   {
+     XmlNode fooEnumMapMapEntryNode = fooEnumMapParentNode.CreateChildElement("entry");
+     XmlNode fooEnumMapKeyNode = fooEnumMapMapEntryNode.CreateChildElement("key");
+     fooEnumMapKeyNode.SetText(mapItem.first);
+     XmlNode fooEnumMapValueNode = fooEnumMapMapEntryNode.CreateChildElement("value");
+     fooEnumMapValueNode.SetText(FooEnumMapper::GetNameForFooEnum(mapItem.second));
+   }
   }
 
   return payloadDoc.ConvertToString();
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlIntEnumsRequest.cpp b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlIntEnumsRequest.cpp
index badbf5d4f3c..940edc1082b 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlIntEnumsRequest.cpp
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlIntEnumsRequest.cpp
@@ -84,6 +84,17 @@ Aws::String XmlIntEnumsRequest::SerializePayload() const
 
   if(m_intEnumMapHasBeenSet)
   {
+   XmlNode intEnumMapParentNode = parentNode.CreateChildElement("intEnumMap");
+   for(const auto& mapItem : m_intEnumMap)
+   {
+     XmlNode intEnumMapMapEntryNode = intEnumMapParentNode.CreateChildElement("entry");
+     XmlNode intEnumMapKeyNode = intEnumMapMapEntryNode.CreateChildElement("key");
+     intEnumMapKeyNode.SetText(mapItem.first);
+     XmlNode intEnumMapValueNode = intEnumMapMapEntryNode.CreateChildElement("value");
+     ss << mapItem.second;
+     intEnumMapValueNode.SetText(ss.str());
+     ss.str("");
+   }
   }
 
   return payloadDoc.ConvertToString();
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlListsRequest.cpp b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlListsRequest.cpp
index c8c3d712bcf..06c1ccb2ab7 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlListsRequest.cpp
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlListsRequest.cpp
@@ -90,7 +90,7 @@ Aws::String XmlListsRequest::SerializePayload() const
    for(const auto& item : m_timestampList)
    {
      XmlNode timestampListNode = timestampListParentNode.CreateChildElement("Timestamp");
-     timestampListNode.SetText(item.ToGmtString(Aws::Utils::DateFormat::ISO_8601);
+     timestampListNode.SetText(item.ToGmtString(Aws::Utils::DateFormat::ISO_8601));
    }
   }
 
@@ -122,6 +122,7 @@ Aws::String XmlListsRequest::SerializePayload() const
    for(const auto& item : m_nestedStringList)
    {
      XmlNode nestedStringListNode = nestedStringListParentNode.CreateChildElement("StringList");
+     nestedStringListNode.SetText(item);
    }
   }
 
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlMapWithXmlNamespaceRequest.cpp b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlMapWithXmlNamespaceRequest.cpp
index 064a582fef2..a4199f4ee09 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlMapWithXmlNamespaceRequest.cpp
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlMapWithXmlNamespaceRequest.cpp
@@ -28,6 +28,15 @@ Aws::String XmlMapWithXmlNamespaceRequest::SerializePayload() const
   Aws::StringStream ss;
   if(m_myMapHasBeenSet)
   {
+   XmlNode myMapParentNode = parentNode.CreateChildElement("KVP");
+   for(const auto& mapItem : m_myMap)
+   {
+     XmlNode myMapMapEntryNode = myMapParentNode.CreateChildElement("KVP");
+     XmlNode myMapKeyNode = myMapMapEntryNode.CreateChildElement("K");
+     myMapKeyNode.SetText(mapItem.first);
+     XmlNode myMapValueNode = myMapMapEntryNode.CreateChildElement("V");
+     myMapValueNode.SetText(mapItem.second);
+   }
   }
 
   return payloadDoc.ConvertToString();
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlMapsRequest.cpp b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlMapsRequest.cpp
index 2751777d24a..ce8e2410264 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlMapsRequest.cpp
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlMapsRequest.cpp
@@ -28,6 +28,15 @@ Aws::String XmlMapsRequest::SerializePayload() const
   Aws::StringStream ss;
   if(m_myMapHasBeenSet)
   {
+   XmlNode myMapParentNode = parentNode.CreateChildElement("myMap");
+   for(const auto& mapItem : m_myMap)
+   {
+     XmlNode myMapMapEntryNode = myMapParentNode.CreateChildElement("entry");
+     XmlNode myMapKeyNode = myMapMapEntryNode.CreateChildElement("key");
+     myMapKeyNode.SetText(mapItem.first);
+     XmlNode myMapValueNode = myMapMapEntryNode.CreateChildElement("value");
+     mapItem.second.AddToNode(myMapValueNode);
+   }
   }
 
   return payloadDoc.ConvertToString();
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlMapsXmlNameRequest.cpp b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlMapsXmlNameRequest.cpp
index 7f22c2b39d0..1cc61334e56 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlMapsXmlNameRequest.cpp
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlMapsXmlNameRequest.cpp
@@ -28,6 +28,15 @@ Aws::String XmlMapsXmlNameRequest::SerializePayload() const
   Aws::StringStream ss;
   if(m_myMapHasBeenSet)
   {
+   XmlNode myMapParentNode = parentNode.CreateChildElement("myMap");
+   for(const auto& mapItem : m_myMap)
+   {
+     XmlNode myMapMapEntryNode = myMapParentNode.CreateChildElement("entry");
+     XmlNode myMapKeyNode = myMapMapEntryNode.CreateChildElement("Attribute");
+     myMapKeyNode.SetText(mapItem.first);
+     XmlNode myMapValueNode = myMapMapEntryNode.CreateChildElement("Setting");
+     mapItem.second.AddToNode(myMapValueNode);
+   }
   }
 
   return payloadDoc.ConvertToString();
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlTimestampsRequest.cpp b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlTimestampsRequest.cpp
index b2a309b5a08..5f2bc11994c 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlTimestampsRequest.cpp
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlTimestampsRequest.cpp
@@ -53,25 +53,25 @@ Aws::String XmlTimestampsRequest::SerializePayload() const
   if(m_epochSecondsHasBeenSet)
   {
    XmlNode epochSecondsNode = parentNode.CreateChildElement("epochSeconds");
-   epochSecondsNode.SetText(m_epochSeconds.ToGmtString(Aws::Utils::DateFormat::ISO_8601));
+   epochSecondsNode.SetText(StringUtils::to_string(m_epochSeconds.Seconds()));
   }
 
   if(m_epochSecondsOnTargetHasBeenSet)
   {
    XmlNode epochSecondsOnTargetNode = parentNode.CreateChildElement("epochSecondsOnTarget");
-   epochSecondsOnTargetNode.SetText(m_epochSecondsOnTarget.ToGmtString(Aws::Utils::DateFormat::ISO_8601));
+   epochSecondsOnTargetNode.SetText(StringUtils::to_string(m_epochSecondsOnTarget.Seconds()));
   }
 
   if(m_httpDateHasBeenSet)
   {
    XmlNode httpDateNode = parentNode.CreateChildElement("httpDate");
-   httpDateNode.SetText(m_httpDate.ToGmtString(Aws::Utils::DateFormat::ISO_8601));
+   httpDateNode.SetText(m_httpDate.ToGmtString(Aws::Utils::DateFormat::RFC822));
   }
 
   if(m_httpDateOnTargetHasBeenSet)
   {
    XmlNode httpDateOnTargetNode = parentNode.CreateChildElement("httpDateOnTarget");
-   httpDateOnTargetNode.SetText(m_httpDateOnTarget.ToGmtString(Aws::Utils::DateFormat::ISO_8601));
+   httpDateOnTargetNode.SetText(m_httpDateOnTarget.ToGmtString(Aws::Utils::DateFormat::RFC822));
   }
 
   return payloadDoc.ConvertToString();
diff --git a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlTimestampsResult.cpp b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlTimestampsResult.cpp
index 87556c10607..d7c70f9922a 100644
--- a/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlTimestampsResult.cpp
+++ b/generated/protocol-tests/test-clients/aws-cpp-sdk-rest-xml-protocol/source/model/XmlTimestampsResult.cpp
@@ -50,12 +50,12 @@ XmlTimestampsResult& XmlTimestampsResult::operator =(const Aws::AmazonWebService
     XmlNode epochSecondsNode = resultNode.FirstChild("epochSeconds");
     if(!epochSecondsNode.IsNull())
     {
-      m_epochSeconds = DateTime(StringUtils::Trim(Aws::Utils::Xml::DecodeEscapedXmlText(epochSecondsNode.GetText()).c_str()).c_str(), Aws::Utils::DateFormat::$CppViewHelper.computeTimestampFormatInXml($member.shape));
+      m_epochSeconds = DateTime(StringUtils::ConvertToDouble(StringUtils::Trim(Aws::Utils::Xml::DecodeEscapedXmlText(epochSecondsNode.GetText()).c_str()).c_str()));
     }
     XmlNode epochSecondsOnTargetNode = resultNode.FirstChild("epochSecondsOnTarget");
     if(!epochSecondsOnTargetNode.IsNull())
     {
-      m_epochSecondsOnTarget = DateTime(StringUtils::Trim(Aws::Utils::Xml::DecodeEscapedXmlText(epochSecondsOnTargetNode.GetText()).c_str()).c_str(), Aws::Utils::DateFormat::$CppViewHelper.computeTimestampFormatInXml($member.shape));
+      m_epochSecondsOnTarget = DateTime(StringUtils::ConvertToDouble(StringUtils::Trim(Aws::Utils::Xml::DecodeEscapedXmlText(epochSecondsOnTargetNode.GetText()).c_str()).c_str()));
     }
     XmlNode httpDateNode = resultNode.FirstChild("httpDate");
     if(!httpDateNode.IsNull())
diff --git a/generated/src/aws-cpp-sdk-s3-crt/source/model/ObjectIdentifier.cpp b/generated/src/aws-cpp-sdk-s3-crt/source/model/ObjectIdentifier.cpp
index cdac3cfd4f4..33889f73f58 100644
--- a/generated/src/aws-cpp-sdk-s3-crt/source/model/ObjectIdentifier.cpp
+++ b/generated/src/aws-cpp-sdk-s3-crt/source/model/ObjectIdentifier.cpp
@@ -101,7 +101,7 @@ void ObjectIdentifier::AddToNode(XmlNode& parentNode) const
   if(m_lastModifiedTimeHasBeenSet)
   {
    XmlNode lastModifiedTimeNode = parentNode.CreateChildElement("LastModifiedTime");
-   lastModifiedTimeNode.SetText(m_lastModifiedTime.ToGmtString(Aws::Utils::DateFormat::ISO_8601));
+   lastModifiedTimeNode.SetText(m_lastModifiedTime.ToGmtString(Aws::Utils::DateFormat::RFC822));
   }
 
   if(m_sizeHasBeenSet)
diff --git a/generated/src/aws-cpp-sdk-s3/source/model/ObjectIdentifier.cpp b/generated/src/aws-cpp-sdk-s3/source/model/ObjectIdentifier.cpp
index 5fa0baeddf9..c923b6e97b7 100644
--- a/generated/src/aws-cpp-sdk-s3/source/model/ObjectIdentifier.cpp
+++ b/generated/src/aws-cpp-sdk-s3/source/model/ObjectIdentifier.cpp
@@ -101,7 +101,7 @@ void ObjectIdentifier::AddToNode(XmlNode& parentNode) const
   if(m_lastModifiedTimeHasBeenSet)
   {
    XmlNode lastModifiedTimeNode = parentNode.CreateChildElement("LastModifiedTime");
-   lastModifiedTimeNode.SetText(m_lastModifiedTime.ToGmtString(Aws::Utils::DateFormat::ISO_8601));
+   lastModifiedTimeNode.SetText(m_lastModifiedTime.ToGmtString(Aws::Utils::DateFormat::RFC822));
   }
 
   if(m_sizeHasBeenSet)
diff --git a/generated/src/aws-cpp-sdk-s3control/source/model/LambdaInvokeOperation.cpp b/generated/src/aws-cpp-sdk-s3control/source/model/LambdaInvokeOperation.cpp
index 663ed63b52c..d26802e9b97 100644
--- a/generated/src/aws-cpp-sdk-s3control/source/model/LambdaInvokeOperation.cpp
+++ b/generated/src/aws-cpp-sdk-s3control/source/model/LambdaInvokeOperation.cpp
@@ -89,6 +89,15 @@ void LambdaInvokeOperation::AddToNode(XmlNode& parentNode) const
 
   if(m_userArgumentsHasBeenSet)
   {
+   XmlNode userArgumentsParentNode = parentNode.CreateChildElement("UserArguments");
+   for(const auto& mapItem : m_userArguments)
+   {
+     XmlNode userArgumentsMapEntryNode = userArgumentsParentNode.CreateChildElement("entry");
+     XmlNode userArgumentsKeyNode = userArgumentsMapEntryNode.CreateChildElement("key");
+     userArgumentsKeyNode.SetText(mapItem.first);
+     XmlNode userArgumentsValueNode = userArgumentsMapEntryNode.CreateChildElement("value");
+     userArgumentsValueNode.SetText(mapItem.second);
+   }
   }
 
 }
diff --git a/generated/src/aws-cpp-sdk-s3control/source/model/S3ObjectMetadata.cpp b/generated/src/aws-cpp-sdk-s3control/source/model/S3ObjectMetadata.cpp
index c1ff8c7f78f..c136a1ad706 100644
--- a/generated/src/aws-cpp-sdk-s3control/source/model/S3ObjectMetadata.cpp
+++ b/generated/src/aws-cpp-sdk-s3control/source/model/S3ObjectMetadata.cpp
@@ -160,6 +160,15 @@ void S3ObjectMetadata::AddToNode(XmlNode& parentNode) const
 
   if(m_userMetadataHasBeenSet)
   {
+   XmlNode userMetadataParentNode = parentNode.CreateChildElement("UserMetadata");
+   for(const auto& mapItem : m_userMetadata)
+   {
+     XmlNode userMetadataMapEntryNode = userMetadataParentNode.CreateChildElement("entry");
+     XmlNode userMetadataKeyNode = userMetadataMapEntryNode.CreateChildElement("key");
+     userMetadataKeyNode.SetText(mapItem.first);
+     XmlNode userMetadataValueNode = userMetadataMapEntryNode.CreateChildElement("value");
+     userMetadataValueNode.SetText(mapItem.second);
+   }
   }
 
   if(m_contentLengthHasBeenSet)
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/queryxml/QueryXmlSubObjectHeader.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/queryxml/QueryXmlSubObjectHeader.vm
index 7cf7452553a..1fb5ec8a0c5 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/queryxml/QueryXmlSubObjectHeader.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/queryxml/QueryXmlSubObjectHeader.vm
@@ -29,6 +29,9 @@ namespace ${serviceNamespace}
 {
 namespace Model
 {
+#foreach($forwardDeclaration in $typeInfo.forwardDeclarations)
+  class $forwardDeclaration;
+#end
 #set($xmlRef = "${typeInfo.xmlNodeType}&")
 #set($classNameRef = "${typeInfo.className}&")
 
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/ModelClassMemberSingleXmlizeSource.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/ModelClassMemberSingleXmlizeSource.vm
new file mode 100644
index 00000000000..238400e6d88
--- /dev/null
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/ModelClassMemberSingleXmlizeSource.vm
@@ -0,0 +1,136 @@
+##-------------------- serializeElementToText macro
+#macro( serializeElementToText $shapeMember $memberVarName )
+##/* --- the actual shape member is $shapeMember; the actual shape is $shapeMember.shape; --- */
+#if($shapeMember.shape.enum)
+${shapeMember.shape.name}Mapper::GetNameFor${shapeMember.shape.name}(${memberVarName})##
+#elseif($shapeMember.shape.timeStamp)
+#if($member.shape.timestampFormat != "unixTimestamp")
+#set($timestamptFormatStr = $CppViewHelper.computeTimestampFormatInXml($shapeMember.shape))
+${memberVarName}.ToGmtString(Aws::Utils::DateFormat::${timestamptFormatStr})##
+#else
+StringUtils::to_string(${memberVarName}.Seconds())##
+#end
+#elseif($shapeMember.shape.boolean)
+std::boolalpha << ${memberVarName}##
+#elseif($shapeMember.shape.blob)
+HashingUtils::Base64Encode(${memberVarName})##
+#else
+${memberVarName}##
+#end
+#end##macro serializeElementToText
+##-------------------- serializeXmlPayloadElement macro
+#macro( serializeXmlPayloadElement $spaces $serializationName $lowerCaseVarName $shapeMember $memberVarName $parentNode="parentNode")
+#if($shapeMember.xmlAttribute)
+#if($shapeMember.shape.boolean || $shapeMember.shape.primitive)
+  ${spaces}ss << #serializeElementToText($shapeMember, $memberVarName);
+  ${spaces}${parentNode}.SetAttributeValue("${serializationName}", ss.str());
+  ${spaces}ss.str("");
+#else
+  ${spaces}${parentNode}.SetAttributeValue("${serializationName}", #serializeElementToText($shapeMember, $memberVarName));
+#end
+#else##($shapeMember.xmlAttribute)
+  ${spaces}XmlNode ${lowerCaseVarName}Node = ${parentNode}.CreateChildElement("${serializationName}");
+#if($shapeMember.shape.boolean || $shapeMember.shape.primitive)
+  ${spaces}ss << #serializeElementToText($shapeMember, $memberVarName);
+  ${spaces}${lowerCaseVarName}Node.SetText(ss.str());
+  ${spaces}ss.str("");
+#else
+#if($shapeMember.shape.structure)
+  ${spaces}${memberVarName}.AddToNode(${lowerCaseVarName}Node);
+#else
+  ${spaces}${lowerCaseVarName}Node.SetText(#serializeElementToText($shapeMember, $memberVarName));
+#end
+#end
+#end
+#end##macro serializeXmlPayloadElement
+##-------------------- serializeXmlListPayloadElement macro
+#macro( serializeXmlListPayloadElement $spaces $serializationName $lowerCaseVarName $member $memberVarName )
+#if(!($member.locationName && $member.shape.flattened) && !(${member.shape.listMember.locationName} && ${member.isFlattened()}))
+  ${spaces}XmlNode ${lowerCaseVarName}ParentNode = parentNode.CreateChildElement("${serializationName}");
+#end
+  ${spaces}for(const auto& item : $memberVarName)
+  ${spaces}{
+#set($listElParentNode = "parentNode")
+#set($listElSerializationName = "")
+#if($member.locationName && $member.shape.flattened)
+#set($listElSerializationName = ${member.locationName})
+#elseif(${member.shape.listMember.locationName} && ${member.isFlattened()})
+#set($listElSerializationName = ${member.shape.listMember.locationName})
+#elseif(${member.shape.listMember.locationName})
+#set($listElSerializationName = ${member.shape.listMember.locationName})
+#set($listElParentNode = "${lowerCaseVarName}ParentNode")
+#else
+#set($listElSerializationName = ${member.shape.listMember.shape.name})
+#set($listElParentNode = "${lowerCaseVarName}ParentNode")
+#end
+#set($listSpaces = $spaces + "  ")
+#serializeXmlPayloadElement($listSpaces, $listElSerializationName, $lowerCaseVarName, $member.shape.listMember, "item", $listElParentNode)
+  ${spaces}}
+#end##macro serializeXmlListPayloadElement
+##-------------------- serializeXmlMapPayloadElement macro
+#macro( serializeXmlMapPayloadElement $spaces $serializationName $lowerCaseVarName $member $memberVarName )
+##https://smithy.io/2.0/spec/protocol-traits.html#xml-map-serialization
+##TODO: might not be 100% correct, pending validation by protocol tests
+##// /* --- the actual shape member is $member; the actual shape is $member.shape; --- */
+##// /* --- key member: ${member.shape.mapKey} */
+##// /* --- key shape: ${member.shape.mapKey.shape} */
+##// /* --- key member: ${member.shape.mapValue} */
+##// /* --- key shape: ${member.shape.mapValue.shape} */
+#set($mapEntryParentNode = "parentNode")
+#if(!($member.locationName && $member.shape.flattened))
+  ${spaces}XmlNode ${lowerCaseVarName}ParentNode = parentNode.CreateChildElement("${serializationName}");
+#set($mapEntryParentNode = "${lowerCaseVarName}ParentNode")
+#end
+  ${spaces}for(const auto& mapItem : $memberVarName)
+  ${spaces}{
+#set($mapSpaces = $spaces + "  ")
+#set($mapEntrySerializationName = "#if($member.locationName)$member.locationName#{else}entry#end")
+  ${spaces}  XmlNode ${lowerCaseVarName}MapEntryNode = ${mapEntryParentNode}.CreateChildElement("${mapEntrySerializationName}");
+#set($mapKeySerializationName = "#if($member.shape.mapKey.locationName)$member.shape.mapKey.locationName#{else}key#end")
+#serializeXmlPayloadElement($mapSpaces, $mapKeySerializationName, "${lowerCaseVarName}Key", $member.shape.mapKey, "mapItem.first", "${lowerCaseVarName}MapEntryNode")
+#set($mapValueSerializationName = "#if($member.shape.mapValue.locationName)$member.shape.mapValue.locationName#{else}value#end")
+#serializeXmlPayloadElement($mapSpaces, $mapValueSerializationName, "${lowerCaseVarName}Value", $member.shape.mapValue, "mapItem.second", "${lowerCaseVarName}MapEntryNode")
+  ${spaces}}
+#end##macro serializeXmlMapPayloadElement
+##-------------------- END OF MACROS, ACTUAL TEMPLATE BEGINS --------------------
+#if($member.shape.enum || $member.shape.boolean || $member.shape.primitive || $member.shape.timeStamp || $member.shape.structure || $member.shape.blob)
+#serializeXmlPayloadElement($spaces, $serializationName, $lowerCaseVarName, $member, $memberVarName)
+#elseif($member.shape.string)
+#if($member.xmlAttribute)
+  ${spaces}parentNode.SetAttributeValue("${serializationName}", ${memberVarName});
+#else
+  ${spaces}XmlNode ${lowerCaseVarName}Node = parentNode.CreateChildElement("${serializationName}");
+#if($operation.arnEndpointAllowed && $operation.arnLocation.equals("body") && $operation.arnEndpointMemberName.equals($memberName) && !$serviceModel.endpointRules))
+## TODO: just remove this block once endpoints check can be removed
+  ${spaces}${metadata.classNamePrefix}ARN arn($CppViewHelper.computeMemberVariableName($operation.arnEndpointMemberName));
+  ${spaces}if (arn && arn.Validate().IsSuccess())
+  ${spaces}{
+  ${spaces}  if (arn.GetResourceType() == ARNResourceType::BUCKET)
+  ${spaces}  {
+  ${spaces}    ${lowerCaseVarName}Node.SetText(arn.GetResourceId());
+  ${spaces}  }
+  ${spaces}  else if (arn.GetResourceType() == ARNResourceType::OUTPOST)
+  ${spaces}  {
+  ${spaces}    ${lowerCaseVarName}Node.SetText(arn.GetSubResourceId());
+  ${spaces}  }
+  ${spaces}  else
+  ${spaces}  {
+  ${spaces}    // It's a valid ARN, but has incorrect resource type.
+  ${spaces}    assert(false);
+  ${spaces}  }
+  ${spaces}}
+  ${spaces}else
+  ${spaces}{
+  ${spaces}  ${lowerCaseVarName}Node.SetText(${memberVarName});
+  ${spaces}}
+#else
+  ${spaces}${lowerCaseVarName}Node.SetText(${memberVarName});
+#end##$operation.arnEndpointAllowed...
+#end
+#elseif($member.shape.list)
+#serializeXmlListPayloadElement($spaces, $serializationName, $lowerCaseVarName, $member, $memberVarName)
+#elseif($member.shape.map)
+#serializeXmlMapPayloadElement($spaces, $serializationName, $lowerCaseVarName, $member, $memberVarName)
+#else
+!!!! Code generation error: the template does not support this shape under $serializationName serialization to xml: ${member}
+#end##End of member.shape is structure or list
\ No newline at end of file
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/ModelClassMembersDeserializeXml.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/ModelClassMembersDeserializeXml.vm
index 99a517ce21a..03ce3398639 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/ModelClassMembersDeserializeXml.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/ModelClassMembersDeserializeXml.vm
@@ -177,7 +177,11 @@
 #elseif($member.shape.string)
     ${spaces}${memberVarName} = ${substituteString};
 #elseif($member.shape.timeStamp)
+#if($member.shape.timestampFormat != "unixTimestamp")
     ${spaces}${memberVarName} = DateTime(StringUtils::Trim(${substituteString}.c_str()).c_str(), Aws::Utils::DateFormat::$CppViewHelper.computeTimestampFormatInXml($member.shape));
+#else
+    ${spaces}${memberVarName} = DateTime(StringUtils::ConvertToDouble(StringUtils::Trim(${substituteString}.c_str()).c_str()));
+#end
 #end
 #if(!$member.required && $useRequiredField)
       $varNameHasBeenSet = true;
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/ModelClassMembersXmlizeSource.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/ModelClassMembersXmlizeSource.vm
index 43d554112b0..8f6aa0d1476 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/ModelClassMembersXmlizeSource.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/ModelClassMembersXmlizeSource.vm
@@ -28,117 +28,7 @@
   if($varNameHasBeenSet)
   {
 #end
-#if($member.shape.enum)
-#if($member.xmlAttribute)
-  ${spaces}parentNode.SetAttributeValue("${serializationName}", ${member.shape.name}Mapper::GetNameFor${member.shape.name}(${memberVarName}));
-#else
-  ${spaces}XmlNode ${lowerCaseVarName}Node = parentNode.CreateChildElement("${serializationName}");
-  ${spaces}${lowerCaseVarName}Node.SetText(${member.shape.name}Mapper::GetNameFor${member.shape.name}(${memberVarName}));
-#end
-#elseif($member.shape.boolean)
-#if($member.xmlAttribute)
-  ${spaces}ss << std::boolalpha << ${memberVarName};
-  ${spaces}parentNode.SetAttributeValue("${serializationName}", ss.str());
-#else
-  ${spaces}XmlNode ${lowerCaseVarName}Node = parentNode.CreateChildElement("${serializationName}");
-  ${spaces}ss << std::boolalpha << ${memberVarName};
-  ${spaces}${lowerCaseVarName}Node.SetText(ss.str());
-#end
-  ${spaces}ss.str("");
-#elseif($member.shape.primitive)
-#if($member.xmlAttribute)
-  ${spaces}ss << ${memberVarName};
-  ${spaces}parentNode.SetAttributeValue("${serializationName}", ss.str());
-#else
-  ${spaces}XmlNode ${lowerCaseVarName}Node = parentNode.CreateChildElement("${serializationName}");
-  ${spaces}ss << ${memberVarName};
-  ${spaces}${lowerCaseVarName}Node.SetText(ss.str());
-#end
-  ${spaces}ss.str("");
-#elseif($member.shape.string)
-#if($member.xmlAttribute)
-  ${spaces}parentNode.SetAttributeValue("${serializationName}", ${memberVarName});
-#else
-  ${spaces}XmlNode ${lowerCaseVarName}Node = parentNode.CreateChildElement("${serializationName}");
-#if($operation.arnEndpointAllowed && $operation.arnLocation.equals("body") && $operation.arnEndpointMemberName.equals($memberName) && !$serviceModel.endpointRules))
-  ${spaces}${metadata.classNamePrefix}ARN arn($CppViewHelper.computeMemberVariableName($operation.arnEndpointMemberName));
-  ${spaces}if (arn && arn.Validate().IsSuccess())
-  ${spaces}{
-  ${spaces}  if (arn.GetResourceType() == ARNResourceType::BUCKET)
-  ${spaces}  {
-  ${spaces}    ${lowerCaseVarName}Node.SetText(arn.GetResourceId());
-  ${spaces}  }
-  ${spaces}  else if (arn.GetResourceType() == ARNResourceType::OUTPOST)
-  ${spaces}  {
-  ${spaces}    ${lowerCaseVarName}Node.SetText(arn.GetSubResourceId());
-  ${spaces}  }
-  ${spaces}  else
-  ${spaces}  {
-  ${spaces}    // It's a valid ARN, but has incorrect resource type.
-  ${spaces}    assert(false);
-  ${spaces}  }
-  ${spaces}}
-  ${spaces}else
-  ${spaces}{
-  ${spaces}  ${lowerCaseVarName}Node.SetText(${memberVarName});
-  ${spaces}}
-#else
-  ${spaces}${lowerCaseVarName}Node.SetText(${memberVarName});
-#end
-#end
-#elseif($member.shape.timeStamp)
-#if($member.xmlAttribute)
-  ${spaces}parentNode.SetAttributeValue("${serializationName}", ${memberVarName}.ToGmtString(Aws::Utils::DateFormat::$CppViewHelper.computeTimestampFormatInXml($member.shape)));
-#else
-  ${spaces}XmlNode ${lowerCaseVarName}Node = parentNode.CreateChildElement("${serializationName}");
-  ${spaces}${lowerCaseVarName}Node.SetText(${memberVarName}.ToGmtString(Aws::Utils::DateFormat::ISO_8601));
-#end
-#elseif($member.shape.blob)
-#if($member.xmlAttribute)
-  ${spaces}parentNode.SetAttributeValue("${serializationName}", HashingUtils::Base64Encode(${memberVarName}));
-#else
-  ${spaces}XmlNode ${lowerCaseVarName}Node = parentNode.CreateChildElement("${serializationName}");
-  ${spaces}${lowerCaseVarName}Node.SetText(HashingUtils::Base64Encode(${memberVarName}));
-#end
-#elseif($member.shape.structure)
-  ${spaces}XmlNode ${lowerCaseVarName}Node = parentNode.CreateChildElement("${serializationName}");
-  ${spaces}${memberVarName}.AddToNode(${lowerCaseVarName}Node);
-#elseif($member.shape.list)
-#if(!($member.locationName && $member.shape.flattened) && !(${member.shape.listMember.locationName} && ${member.isFlattened()}))
-  ${spaces}XmlNode ${lowerCaseVarName}ParentNode = parentNode.CreateChildElement("${serializationName}");
-#end
-  ${spaces}for(const auto& item : $memberVarName)
-  ${spaces}{
-#if($member.locationName && $member.shape.flattened)
-    ${spaces}XmlNode ${lowerCaseVarName}Node = parentNode.CreateChildElement("${member.locationName}");
-#elseif(${member.shape.listMember.locationName} && ${member.isFlattened()})
-    ${spaces}XmlNode ${lowerCaseVarName}Node = parentNode.CreateChildElement("${member.shape.listMember.locationName}");
-#elseif(${member.shape.listMember.locationName})
-    ${spaces}XmlNode ${lowerCaseVarName}Node = ${lowerCaseVarName}ParentNode.CreateChildElement("${member.shape.listMember.locationName}");
-#else
-    ${spaces}XmlNode ${lowerCaseVarName}Node = ${lowerCaseVarName}ParentNode.CreateChildElement("${member.shape.listMember.shape.name}");
-#end
-#if($member.shape.listMember.shape.enum)
-    ${spaces}${lowerCaseVarName}Node.SetText(${member.shape.listMember.shape.name}Mapper::GetNameFor${member.shape.listMember.shape.name}(item));
-#elseif($member.shape.listMember.shape.boolean)
-    ${spaces}ss << std::boolalpha << item;
-    ${spaces}${lowerCaseVarName}Node.SetText(ss.str());
-    ${spaces}ss.str("");
-#elseif($member.shape.listMember.shape.primitive)
-    ${spaces}ss << item;
-    ${spaces}${lowerCaseVarName}Node.SetText(ss.str());
-    ${spaces}ss.str("");
-#elseif($member.shape.listMember.shape.string)
-    ${spaces}${lowerCaseVarName}Node.SetText(item);
-#elseif($member.shape.listMember.shape.timeStamp)
-    ${spaces}${lowerCaseVarName}Node.SetText(item.ToGmtString(Aws::Utils::DateFormat::$CppViewHelper.computeTimestampFormatInXml($member.shape.listMember.shape));
-#elseif($member.shape.listMember.shape.blob)
-    ${spaces}${lowerCaseVarName}Node.SetText(HashingUtils::Base64Encode(item));
-#elseif($member.shape.listMember.shape.structure)
-    ${spaces}item.AddToNode(${lowerCaseVarName}Node);
-#end
-  ${spaces}}
-#end##End of member.shape is structure or list
+#parse("com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/ModelClassMemberSingleXmlizeSource.vm")
 #if(!$member.required && $useRequiredField)
   }
 
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/XmlRequestSource.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/XmlRequestSource.vm
index efeaee32a8c..099f66012fc 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/XmlRequestSource.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/XmlRequestSource.vm
@@ -69,6 +69,7 @@ Aws::String ${typeInfo.className}::SerializePayload() const
 #set($xmlNamespace = ${payloadMember.xmlNamespace})
 #set($locationName = $payloadMember.locationName)
 #end
+#if(!$payloadMember || !$payloadMember.shape.enum && !$payloadMember.shape.string && !$payloadMember.shape.string)##if payload is structured
 #if($locationName)
   XmlDocument payloadDoc = XmlDocument::CreateWithRootNode("${locationName}");
 #else
@@ -76,6 +77,7 @@ Aws::String ${typeInfo.className}::SerializePayload() const
 #end
 
   XmlNode parentNode = payloadDoc.GetRootElement();
+#end
 #if($xmlNamespace)
 #if($xmlNamespace.prefix)
 #set($xmlnsKey = "xmlns:${xmlNamespace.prefix}")
@@ -86,6 +88,20 @@ Aws::String ${typeInfo.className}::SerializePayload() const
 #end
 
 #if($payloadMember)
+#if($payloadMember.shape.enum || $payloadMember.shape.string || $payloadMember.shape.string)
+##payload member is "streamed", i.e. payload doc is not the XML, but the enum string/string/blob itself
+##and CPP SDK did not generate legacy "streaming" request for some modelling quirks) - we need to set the payload to just a string/buffer.
+#if($payloadMember.shape.enum)
+  if ($payloadMember.shape.name::NOT_SET != ${CppViewHelper.computeMemberVariableName($shape.payload)}) {
+    return ${payloadMember.shape.name}Mapper::GetNameFor${payloadMember.shape.name}(${CppViewHelper.computeMemberVariableName($shape.payload)});
+  }
+  return {};
+#elseif($payloadMember.shape.string)
+  return ${CppViewHelper.computeMemberVariableName($shape.payload)};
+#else
+  static_assert(false, "Failed to generate code to serialize non-streaming request with non-structured (not xml) plain string/blob payload" /*payloadMember: $payloadMember*/);
+#end
+#else
   ${CppViewHelper.computeMemberVariableName($shape.payload)}.AddToNode(parentNode);
   if(parentNode.HasChildren())
   {
@@ -93,6 +109,7 @@ Aws::String ${typeInfo.className}::SerializePayload() const
   }
 
   return {};
+#end
 #else
 #set($useRequiredField = true)
 #set($callFromRequestShape = true)
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/rest/RestXmlSubObjectHeader.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/rest/RestXmlSubObjectHeader.vm
index 919ae5c67f3..33489947c02 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/rest/RestXmlSubObjectHeader.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/rest/RestXmlSubObjectHeader.vm
@@ -28,6 +28,9 @@ namespace ${serviceNamespace}
 {
 namespace Model
 {
+#foreach($forwardDeclaration in $typeInfo.forwardDeclarations)
+  class $forwardDeclaration;
+#end
 #set($xmlRef = "${typeInfo.xmlNodeType}&")
 #set($classNameRef = "${typeInfo.className}&")
 
diff --git a/tools/scripts/codegen/protocol_tests_gen.py b/tools/scripts/codegen/protocol_tests_gen.py
index 42f427a14a3..d817255d686 100644
--- a/tools/scripts/codegen/protocol_tests_gen.py
+++ b/tools/scripts/codegen/protocol_tests_gen.py
@@ -157,10 +157,10 @@ def _collect_test_client_models(self) -> dict:
                                                               PROTOCOL_TESTS_ENDPOINT_RULES, None, use_smithy)
         return service_models
 
-    def _get_client_models_metadata(self) -> set:
-        models = set()
+    def _get_client_models_metadata(self) -> list:
+        models = list()
         model_files = os.listdir(self.client_models_dir)
-        for filename in model_files:
+        for filename in sorted(model_files):
             if not os.path.isfile("/".join([self.client_models_dir, filename])):
                 continue
             model_abspath = str(pathlib.Path(f"{self.client_models_dir}/{filename}").resolve())
@@ -169,7 +169,7 @@ def _get_client_models_metadata(self) -> set:
                     c2j_model = json.load(file_content)
                     model_metadata = self.ProtoTestC2jClientModelMetadata(filename, model_abspath,
                                                                           c2j_model.get("metadata"))
-                    models.add(model_metadata)
+                    models.append(model_metadata)
                 except Exception as exc:
                     print(f"ERROR: unexpected file content in protocol tests clients dir {self.client_models_dir}. "
                           f"Expected c2j client model, but json metadata kew is missing: {exc}")
@@ -194,7 +194,7 @@ def _collect_test_definition_models(self) -> dict:
 
                 test_def_path = str(pathlib.Path(f"{self.test_definitions_dir}/{test_def_group}/{filename}").resolve())
 
-                def _get_corresponding_test_client(test_clients_md: set, test_path: str) -> list:
+                def _get_corresponding_test_client(test_clients_md: list, test_path: str) -> list:
                     # Get c2j client models matching the test suite
                     # more than 1 is possible (ex: xml and xml with namespace clients for a single test suite)
                     result = list()