diff --git a/modules/openapi-generator-online/.openapi-generator/VERSION b/modules/openapi-generator-online/.openapi-generator/VERSION
index 096bf47efe3..ad121e8340e 100644
--- a/modules/openapi-generator-online/.openapi-generator/VERSION
+++ b/modules/openapi-generator-online/.openapi-generator/VERSION
@@ -1 +1 @@
-3.0.0-SNAPSHOT
\ No newline at end of file
+3.0.1-SNAPSHOT
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppPistacheServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppPistacheServerCodegen.java
index 1bbfafbce37..6467b33edc9 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppPistacheServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppPistacheServerCodegen.java
@@ -219,14 +219,14 @@ public class CppPistacheServerCodegen extends AbstractCppCodegen {
 
                 //TODO: This changes the info about the real type but it is needed to parse the header params
                 if (param.isHeaderParam) {
-                    param.dataType = "Optional<Net::Http::Header::Raw>";
-                    param.baseType = "Optional<Net::Http::Header::Raw>";
+                    param.dataType = "Pistache::Optional<Pistache::Http::Header::Raw>";
+                    param.baseType = "Pistache::Optional<Pistache::Http::Header::Raw>";
                 } else if (param.isQueryParam) {
                     if (param.isPrimitiveType) {
-                        param.dataType = "Optional<" + param.dataType + ">";
+                        param.dataType = "Pistache::Optional<" + param.dataType + ">";
                     } else {
-                        param.dataType = "Optional<" + param.baseType + ">";
-                        param.baseType = "Optional<" + param.baseType + ">";
+                        param.dataType = "Pistache::Optional<" + param.baseType + ">";
+                        param.baseType = "Pistache::Optional<" + param.baseType + ">";
                     }
                 }
             }
@@ -299,7 +299,7 @@ public class CppPistacheServerCodegen extends AbstractCppCodegen {
             return toModelName(openAPIType);
         }
 
-        return "std::shared_ptr<" + openAPIType + ">";
+        return openAPIType;
     }
 
     @Override
@@ -326,30 +326,14 @@ public class CppPistacheServerCodegen extends AbstractCppCodegen {
         } else if (ModelUtils.isArraySchema(p)) {
             ArraySchema ap = (ArraySchema) p;
             String inner = getSchemaType(ap.getItems());
-            if (!languageSpecificPrimitives.contains(inner)) {
-                inner = "std::shared_ptr<" + inner + ">";
-            }
             return "std::vector<" + inner + ">()";
         } else if (!StringUtils.isEmpty(p.get$ref())) { // model
-            return "new " + toModelName(ModelUtils.getSimpleRef(p.get$ref())) + "()";
+            return toModelName(ModelUtils.getSimpleRef(p.get$ref())) + "()";
         } else if (ModelUtils.isStringSchema(p)) {
             return "\"\"";
         }
 
-        return "nullptr";
-    }
-
-    @Override
-    public void postProcessParameter(CodegenParameter parameter) {
-        super.postProcessParameter(parameter);
-
-        boolean isPrimitiveType = parameter.isPrimitiveType == Boolean.TRUE;
-        boolean isListContainer = parameter.isListContainer == Boolean.TRUE;
-        boolean isString = parameter.isString == Boolean.TRUE;
-
-        if (!isPrimitiveType && !isListContainer && !isString && !parameter.dataType.startsWith("std::shared_ptr")) {
-            parameter.dataType = "std::shared_ptr<" + parameter.dataType + ">";
-        }
+        return "";
     }
 
     /**
diff --git a/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-header.mustache b/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-header.mustache
index 735fe5c1b7b..1ede8d1a982 100644
--- a/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-header.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-header.mustache
@@ -14,6 +14,8 @@
 #include <pistache/router.h>
 #include <pistache/http_headers.h>
 
+#include <pistache/optional.h>
+
 {{#imports}}{{{import}}}
 {{/imports}}
 
@@ -41,7 +43,7 @@ private:
     {{/operation}}
     void {{classnameSnakeLowerCase}}_default_handler(const Pistache::Rest::Request &request, Pistache::Http::ResponseWriter response);
 
-    std::shared_ptr<Pistache::Http::Endpoint> httpEndpoint;
+    Pistache::Http::Endpoint httpEndpoint;
     Pistache::Rest::Router router;
 
     {{#operation}}
diff --git a/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-impl-header.mustache b/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-impl-header.mustache
index b253948959b..3aa6d5bc421 100644
--- a/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-impl-header.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-impl-header.mustache
@@ -17,6 +17,8 @@
 
 #include <{{classname}}.h>
 
+#include <pistache/optional.h>
+
 {{#imports}}{{{import}}}
 {{/imports}}
 
diff --git a/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-source.mustache b/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-source.mustache
index 2545aca76aa..d815ce10ab7 100644
--- a/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-source.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-source.mustache
@@ -10,24 +10,24 @@ namespace {{this}} {
 using namespace {{modelNamespace}};
 
 {{classname}}::{{classname}}(Pistache::Address addr)
-    : httpEndpoint(std::make_shared<Pistache::Http::Endpoint>(addr))
+    : httpEndpoint(addr)
 { };
 
 void {{classname}}::init(size_t thr = 2) {
     auto opts = Pistache::Http::Endpoint::options()
         .threads(thr)
         .flags(Pistache::Tcp::Options::InstallSignalHandler);
-    httpEndpoint->init(opts);
+    httpEndpoint.init(opts);
     setupRoutes();
 }
 
 void {{classname}}::start() {
-    httpEndpoint->setHandler(router.handler());
-    httpEndpoint->serve();
+    httpEndpoint.setHandler(router.handler());
+    httpEndpoint.serve();
 }
 
 void {{classname}}::shutdown() {
-    httpEndpoint->shutdown();
+    httpEndpoint.shutdown();
 }
 
 void {{classname}}::setupRoutes() {
diff --git a/modules/openapi-generator/src/main/resources/cpp-pistache-server/model-header.mustache b/modules/openapi-generator/src/main/resources/cpp-pistache-server/model-header.mustache
index 7b095876a38..3efd24758f5 100644
--- a/modules/openapi-generator/src/main/resources/cpp-pistache-server/model-header.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-pistache-server/model-header.mustache
@@ -45,7 +45,7 @@ public:
     /// </summary>
     {{^isNotContainer}}{{{dataType}}}& {{getter}}();
     {{/isNotContainer}}{{#isNotContainer}}{{{dataType}}} {{getter}}() const;
-    void {{setter}}({{{dataType}}} value);
+    void {{setter}}({{{dataType}}} const{{^isPrimitiveType}}&{{/isPrimitiveType}} value);
     {{/isNotContainer}}{{^required}}bool {{nameInCamelCase}}IsSet() const;
     void unset{{name}}();
     {{/required}}
diff --git a/modules/openapi-generator/src/main/resources/cpp-pistache-server/model-source.mustache b/modules/openapi-generator/src/main/resources/cpp-pistache-server/model-source.mustache
index 49f3d1cea59..b2434df4670 100644
--- a/modules/openapi-generator/src/main/resources/cpp-pistache-server/model-source.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-pistache-server/model-source.mustache
@@ -84,7 +84,7 @@ void {{classname}}::fromJson(nlohmann::json& val)
             else
             {
                 {{{items.datatype}}} newItem({{{items.defaultValue}}});
-                newItem->fromJson(item);
+                newItem.fromJson(item);
                 m_{{name}}.push_back( newItem );
             }
             {{/items.isDateTime}}{{/items.isString}}{{/isPrimitiveType}}
@@ -100,7 +100,7 @@ void {{classname}}::fromJson(nlohmann::json& val)
         {{/isDateTime}}{{^isDateTime}}if(!val["{{baseName}}"].is_null())
         {
             {{{dataType}}} newItem({{{defaultValue}}});
-            newItem->fromJson(val["{{baseName}}"]);
+            newItem.fromJson(val["{{baseName}}"]);
             {{setter}}( newItem );
         }
         {{/isDateTime}}{{/isString}}
@@ -119,7 +119,7 @@ void {{classname}}::fromJson(nlohmann::json& val)
 {
     return m_{{name}};
 }
-void {{classname}}::{{setter}}({{{dataType}}} value)
+void {{classname}}::{{setter}}({{{dataType}}} const{{^isPrimitiveType}}&{{/isPrimitiveType}} value)
 {
     m_{{name}} = value;
     {{^required}}m_{{name}}IsSet = true;{{/required}}
diff --git a/modules/openapi-generator/src/main/resources/cpp-pistache-server/modelbase-header.mustache b/modules/openapi-generator/src/main/resources/cpp-pistache-server/modelbase-header.mustache
index 3c18cede5ec..2e43bb7b853 100644
--- a/modules/openapi-generator/src/main/resources/cpp-pistache-server/modelbase-header.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-pistache-server/modelbase-header.mustache
@@ -28,13 +28,13 @@ public:
     virtual nlohmann::json toJson() const = 0;
     virtual void fromJson(nlohmann::json& json) = 0;
 
-    static std::string toJson( const std::string& value );
-    static std::string toJson( const std::time_t& value );
-    static int32_t toJson( int32_t value );
-    static int64_t toJson( int64_t value );
-    static double toJson( double value );
-    static bool toJson( bool value );
-    static nlohmann::json toJson( std::shared_ptr<ModelBase> content );
+    static std::string toJson(  std::string const& value );
+    static std::string toJson(  std::time_t const& value );
+    static int32_t toJson( int32_t const value );
+    static int64_t toJson( int64_t const value );
+    static double toJson( double const value );
+    static bool toJson( bool const value );
+    static nlohmann::json toJson(ModelBase const& content );
 
 };
 
diff --git a/modules/openapi-generator/src/main/resources/cpp-pistache-server/modelbase-source.mustache b/modules/openapi-generator/src/main/resources/cpp-pistache-server/modelbase-source.mustache
index f209bb68761..a5ec9406c42 100644
--- a/modules/openapi-generator/src/main/resources/cpp-pistache-server/modelbase-source.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-pistache-server/modelbase-source.mustache
@@ -12,41 +12,41 @@ ModelBase::~ModelBase()
 {
 }
 
-std::string ModelBase::toJson( const std::string& value )
+std::string ModelBase::toJson( std::string const& value )
 {
     return value;
 }
 
-std::string ModelBase::toJson( const std::time_t& value )
+std::string ModelBase::toJson( std::time_t const& value )
 {
     char buf[sizeof "2011-10-08T07:07:09Z"];
     strftime(buf, sizeof buf, "%FT%TZ", gmtime(&value));
     return buf;
 }
 
-int32_t ModelBase::toJson( int32_t value )
+int32_t ModelBase::toJson( int32_t const value )
 {
     return value;
 }
 
-int64_t ModelBase::toJson( int64_t value )
+int64_t ModelBase::toJson( int64_t const value )
 {
     return value;
 }
 
-double ModelBase::toJson( double value )
+double ModelBase::toJson( double const value )
 {
     return value;
 }
 
-bool ModelBase::toJson( bool value )
+bool ModelBase::toJson( bool const value )
 {
     return value;
 }
 
-nlohmann::json ModelBase::toJson( std::shared_ptr<ModelBase> content )
+nlohmann::json ModelBase::toJson(ModelBase content )
 {
-    return content.get() ? content->toJson() : nlohmann::json();
+    return content.toJson();
 }
 
 {{#modelNamespaceDeclarations}}
diff --git a/samples/server/petstore/cpp-pistache/.openapi-generator/VERSION b/samples/server/petstore/cpp-pistache/.openapi-generator/VERSION
index 096bf47efe3..1c00c518154 100644
--- a/samples/server/petstore/cpp-pistache/.openapi-generator/VERSION
+++ b/samples/server/petstore/cpp-pistache/.openapi-generator/VERSION
@@ -1 +1 @@
-3.0.0-SNAPSHOT
\ No newline at end of file
+3.0.2-SNAPSHOT
\ No newline at end of file
diff --git a/samples/server/petstore/cpp-pistache/api/PetApi.cpp b/samples/server/petstore/cpp-pistache/api/PetApi.cpp
index 90d1e18c168..c06c5fb1870 100644
--- a/samples/server/petstore/cpp-pistache/api/PetApi.cpp
+++ b/samples/server/petstore/cpp-pistache/api/PetApi.cpp
@@ -20,24 +20,24 @@ namespace api {
 using namespace org::openapitools::server::model;
 
 PetApi::PetApi(Pistache::Address addr)
-    : httpEndpoint(std::make_shared<Pistache::Http::Endpoint>(addr))
+    : httpEndpoint(addr)
 { };
 
 void PetApi::init(size_t thr = 2) {
     auto opts = Pistache::Http::Endpoint::options()
         .threads(thr)
         .flags(Pistache::Tcp::Options::InstallSignalHandler);
-    httpEndpoint->init(opts);
+    httpEndpoint.init(opts);
     setupRoutes();
 }
 
 void PetApi::start() {
-    httpEndpoint->setHandler(router.handler());
-    httpEndpoint->serve();
+    httpEndpoint.setHandler(router.handler());
+    httpEndpoint.serve();
 }
 
 void PetApi::shutdown() {
-    httpEndpoint->shutdown();
+    httpEndpoint.shutdown();
 }
 
 void PetApi::setupRoutes() {
diff --git a/samples/server/petstore/cpp-pistache/api/PetApi.h b/samples/server/petstore/cpp-pistache/api/PetApi.h
index c5950fa4fae..4300dec560c 100644
--- a/samples/server/petstore/cpp-pistache/api/PetApi.h
+++ b/samples/server/petstore/cpp-pistache/api/PetApi.h
@@ -24,6 +24,8 @@
 #include <pistache/router.h>
 #include <pistache/http_headers.h>
 
+#include <pistache/optional.h>
+
 #include "ApiResponse.h"
 #include "Pet.h"
 #include <string>
@@ -58,7 +60,7 @@ private:
     void upload_file_handler(const Pistache::Rest::Request &request, Pistache::Http::ResponseWriter response);
     void pet_api_default_handler(const Pistache::Rest::Request &request, Pistache::Http::ResponseWriter response);
 
-    std::shared_ptr<Pistache::Http::Endpoint> httpEndpoint;
+    Pistache::Http::Endpoint httpEndpoint;
     Pistache::Rest::Router router;
 
 
@@ -79,7 +81,7 @@ private:
     /// </remarks>
     /// <param name="petId">Pet id to delete</param>
     /// <param name="apiKey"> (optional)</param>
-    virtual void delete_pet(const int64_t &petId, const Optional<Net::Http::Header::Raw> &apiKey, Pistache::Http::ResponseWriter &response) = 0;
+    virtual void delete_pet(const int64_t &petId, const Pistache::Optional<Pistache::Http::Header::Raw> &apiKey, Pistache::Http::ResponseWriter &response) = 0;
 
     /// <summary>
     /// Finds Pets by status
@@ -88,7 +90,7 @@ private:
     /// Multiple status values can be provided with comma separated strings
     /// </remarks>
     /// <param name="status">Status values that need to be considered for filter</param>
-    virtual void find_pets_by_status(const Optional<std::string> &status, Pistache::Http::ResponseWriter &response) = 0;
+    virtual void find_pets_by_status(const Pistache::Optional<std::string> &status, Pistache::Http::ResponseWriter &response) = 0;
 
     /// <summary>
     /// Finds Pets by tags
@@ -97,7 +99,7 @@ private:
     /// Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.
     /// </remarks>
     /// <param name="tags">Tags to filter by</param>
-    virtual void find_pets_by_tags(const Optional<std::string> &tags, Pistache::Http::ResponseWriter &response) = 0;
+    virtual void find_pets_by_tags(const Pistache::Optional<std::string> &tags, Pistache::Http::ResponseWriter &response) = 0;
 
     /// <summary>
     /// Find pet by ID
diff --git a/samples/server/petstore/cpp-pistache/api/StoreApi.cpp b/samples/server/petstore/cpp-pistache/api/StoreApi.cpp
index ed8d2bb3568..eea7fe58ea9 100644
--- a/samples/server/petstore/cpp-pistache/api/StoreApi.cpp
+++ b/samples/server/petstore/cpp-pistache/api/StoreApi.cpp
@@ -20,24 +20,24 @@ namespace api {
 using namespace org::openapitools::server::model;
 
 StoreApi::StoreApi(Pistache::Address addr)
-    : httpEndpoint(std::make_shared<Pistache::Http::Endpoint>(addr))
+    : httpEndpoint(addr)
 { };
 
 void StoreApi::init(size_t thr = 2) {
     auto opts = Pistache::Http::Endpoint::options()
         .threads(thr)
         .flags(Pistache::Tcp::Options::InstallSignalHandler);
-    httpEndpoint->init(opts);
+    httpEndpoint.init(opts);
     setupRoutes();
 }
 
 void StoreApi::start() {
-    httpEndpoint->setHandler(router.handler());
-    httpEndpoint->serve();
+    httpEndpoint.setHandler(router.handler());
+    httpEndpoint.serve();
 }
 
 void StoreApi::shutdown() {
-    httpEndpoint->shutdown();
+    httpEndpoint.shutdown();
 }
 
 void StoreApi::setupRoutes() {
diff --git a/samples/server/petstore/cpp-pistache/api/StoreApi.h b/samples/server/petstore/cpp-pistache/api/StoreApi.h
index a243444e8fa..7068fcde620 100644
--- a/samples/server/petstore/cpp-pistache/api/StoreApi.h
+++ b/samples/server/petstore/cpp-pistache/api/StoreApi.h
@@ -24,6 +24,8 @@
 #include <pistache/router.h>
 #include <pistache/http_headers.h>
 
+#include <pistache/optional.h>
+
 #include "Order.h"
 #include <map>
 #include <string>
@@ -54,7 +56,7 @@ private:
     void place_order_handler(const Pistache::Rest::Request &request, Pistache::Http::ResponseWriter response);
     void store_api_default_handler(const Pistache::Rest::Request &request, Pistache::Http::ResponseWriter response);
 
-    std::shared_ptr<Pistache::Http::Endpoint> httpEndpoint;
+    Pistache::Http::Endpoint httpEndpoint;
     Pistache::Rest::Router router;
 
 
diff --git a/samples/server/petstore/cpp-pistache/api/UserApi.cpp b/samples/server/petstore/cpp-pistache/api/UserApi.cpp
index a2889d6a70a..eade7bdf8b7 100644
--- a/samples/server/petstore/cpp-pistache/api/UserApi.cpp
+++ b/samples/server/petstore/cpp-pistache/api/UserApi.cpp
@@ -20,24 +20,24 @@ namespace api {
 using namespace org::openapitools::server::model;
 
 UserApi::UserApi(Pistache::Address addr)
-    : httpEndpoint(std::make_shared<Pistache::Http::Endpoint>(addr))
+    : httpEndpoint(addr)
 { };
 
 void UserApi::init(size_t thr = 2) {
     auto opts = Pistache::Http::Endpoint::options()
         .threads(thr)
         .flags(Pistache::Tcp::Options::InstallSignalHandler);
-    httpEndpoint->init(opts);
+    httpEndpoint.init(opts);
     setupRoutes();
 }
 
 void UserApi::start() {
-    httpEndpoint->setHandler(router.handler());
-    httpEndpoint->serve();
+    httpEndpoint.setHandler(router.handler());
+    httpEndpoint.serve();
 }
 
 void UserApi::shutdown() {
-    httpEndpoint->shutdown();
+    httpEndpoint.shutdown();
 }
 
 void UserApi::setupRoutes() {
diff --git a/samples/server/petstore/cpp-pistache/api/UserApi.h b/samples/server/petstore/cpp-pistache/api/UserApi.h
index 623bf8b6508..08739d309ba 100644
--- a/samples/server/petstore/cpp-pistache/api/UserApi.h
+++ b/samples/server/petstore/cpp-pistache/api/UserApi.h
@@ -24,6 +24,8 @@
 #include <pistache/router.h>
 #include <pistache/http_headers.h>
 
+#include <pistache/optional.h>
+
 #include "User.h"
 #include <string>
 #include <vector>
@@ -58,7 +60,7 @@ private:
     void update_user_handler(const Pistache::Rest::Request &request, Pistache::Http::ResponseWriter response);
     void user_api_default_handler(const Pistache::Rest::Request &request, Pistache::Http::ResponseWriter response);
 
-    std::shared_ptr<Pistache::Http::Endpoint> httpEndpoint;
+    Pistache::Http::Endpoint httpEndpoint;
     Pistache::Rest::Router router;
 
 
@@ -78,7 +80,7 @@ private:
     /// 
     /// </remarks>
     /// <param name="user">List of user object</param>
-    virtual void create_users_with_array_input(const std::vector<std::shared_ptr<User>> &user, Pistache::Http::ResponseWriter &response) = 0;
+    virtual void create_users_with_array_input(const std::vector<User> &user, Pistache::Http::ResponseWriter &response) = 0;
 
     /// <summary>
     /// Creates list of users with given input array
@@ -87,7 +89,7 @@ private:
     /// 
     /// </remarks>
     /// <param name="user">List of user object</param>
-    virtual void create_users_with_list_input(const std::vector<std::shared_ptr<User>> &user, Pistache::Http::ResponseWriter &response) = 0;
+    virtual void create_users_with_list_input(const std::vector<User> &user, Pistache::Http::ResponseWriter &response) = 0;
 
     /// <summary>
     /// Delete user
@@ -115,7 +117,7 @@ private:
     /// </remarks>
     /// <param name="username">The user name for login</param>
     /// <param name="password">The password for login in clear text</param>
-    virtual void login_user(const Optional<std::string> &username, const Optional<std::string> &password, Pistache::Http::ResponseWriter &response) = 0;
+    virtual void login_user(const Pistache::Optional<std::string> &username, const Pistache::Optional<std::string> &password, Pistache::Http::ResponseWriter &response) = 0;
 
     /// <summary>
     /// Logs out current logged in user session
diff --git a/samples/server/petstore/cpp-pistache/impl/PetApiImpl.cpp b/samples/server/petstore/cpp-pistache/impl/PetApiImpl.cpp
index 6e1a5d742f6..e987ecf2371 100644
--- a/samples/server/petstore/cpp-pistache/impl/PetApiImpl.cpp
+++ b/samples/server/petstore/cpp-pistache/impl/PetApiImpl.cpp
@@ -26,13 +26,13 @@ PetApiImpl::PetApiImpl(Pistache::Address addr)
 void PetApiImpl::add_pet(const std::shared_ptr<Pet> &pet, Pistache::Http::ResponseWriter &response) {
     response.send(Pistache::Http::Code::Ok, "Do some magic\n");
 }
-void PetApiImpl::delete_pet(const int64_t &petId, const Optional<Net::Http::Header::Raw> &apiKey, Pistache::Http::ResponseWriter &response) {
+void PetApiImpl::delete_pet(const int64_t &petId, const Pistache::Optional<Pistache::Http::Header::Raw> &apiKey, Pistache::Http::ResponseWriter &response) {
     response.send(Pistache::Http::Code::Ok, "Do some magic\n");
 }
-void PetApiImpl::find_pets_by_status(const Optional<std::string> &status, Pistache::Http::ResponseWriter &response) {
+void PetApiImpl::find_pets_by_status(const Pistache::Optional<std::string> &status, Pistache::Http::ResponseWriter &response) {
     response.send(Pistache::Http::Code::Ok, "Do some magic\n");
 }
-void PetApiImpl::find_pets_by_tags(const Optional<std::string> &tags, Pistache::Http::ResponseWriter &response) {
+void PetApiImpl::find_pets_by_tags(const Pistache::Optional<std::string> &tags, Pistache::Http::ResponseWriter &response) {
     response.send(Pistache::Http::Code::Ok, "Do some magic\n");
 }
 void PetApiImpl::get_pet_by_id(const int64_t &petId, Pistache::Http::ResponseWriter &response) {
diff --git a/samples/server/petstore/cpp-pistache/impl/PetApiImpl.h b/samples/server/petstore/cpp-pistache/impl/PetApiImpl.h
index 020f8993a34..b83c14efb27 100644
--- a/samples/server/petstore/cpp-pistache/impl/PetApiImpl.h
+++ b/samples/server/petstore/cpp-pistache/impl/PetApiImpl.h
@@ -27,6 +27,8 @@
 
 #include <PetApi.h>
 
+#include <pistache/optional.h>
+
 #include "ApiResponse.h"
 #include "Pet.h"
 #include <string>
@@ -44,9 +46,9 @@ public:
     ~PetApiImpl() { };
 
     void add_pet(const std::shared_ptr<Pet> &pet, Pistache::Http::ResponseWriter &response);
-    void delete_pet(const int64_t &petId, const Optional<Net::Http::Header::Raw> &apiKey, Pistache::Http::ResponseWriter &response);
-    void find_pets_by_status(const Optional<std::string> &status, Pistache::Http::ResponseWriter &response);
-    void find_pets_by_tags(const Optional<std::string> &tags, Pistache::Http::ResponseWriter &response);
+    void delete_pet(const int64_t &petId, const Pistache::Optional<Pistache::Http::Header::Raw> &apiKey, Pistache::Http::ResponseWriter &response);
+    void find_pets_by_status(const Pistache::Optional<std::string> &status, Pistache::Http::ResponseWriter &response);
+    void find_pets_by_tags(const Pistache::Optional<std::string> &tags, Pistache::Http::ResponseWriter &response);
     void get_pet_by_id(const int64_t &petId, Pistache::Http::ResponseWriter &response);
     void update_pet(const std::shared_ptr<Pet> &pet, Pistache::Http::ResponseWriter &response);
     void update_pet_with_form(const Pistache::Rest::Request &request, Pistache::Http::ResponseWriter &response);
diff --git a/samples/server/petstore/cpp-pistache/impl/StoreApiImpl.h b/samples/server/petstore/cpp-pistache/impl/StoreApiImpl.h
index 3a7f42923ef..97574ec3ea0 100644
--- a/samples/server/petstore/cpp-pistache/impl/StoreApiImpl.h
+++ b/samples/server/petstore/cpp-pistache/impl/StoreApiImpl.h
@@ -27,6 +27,8 @@
 
 #include <StoreApi.h>
 
+#include <pistache/optional.h>
+
 #include "Order.h"
 #include <map>
 #include <string>
diff --git a/samples/server/petstore/cpp-pistache/impl/UserApiImpl.cpp b/samples/server/petstore/cpp-pistache/impl/UserApiImpl.cpp
index c764c5821da..6d5ce9c5aaf 100644
--- a/samples/server/petstore/cpp-pistache/impl/UserApiImpl.cpp
+++ b/samples/server/petstore/cpp-pistache/impl/UserApiImpl.cpp
@@ -26,10 +26,10 @@ UserApiImpl::UserApiImpl(Pistache::Address addr)
 void UserApiImpl::create_user(const std::shared_ptr<User> &user, Pistache::Http::ResponseWriter &response) {
     response.send(Pistache::Http::Code::Ok, "Do some magic\n");
 }
-void UserApiImpl::create_users_with_array_input(const std::vector<std::shared_ptr<User>> &user, Pistache::Http::ResponseWriter &response) {
+void UserApiImpl::create_users_with_array_input(const std::vector<User> &user, Pistache::Http::ResponseWriter &response) {
     response.send(Pistache::Http::Code::Ok, "Do some magic\n");
 }
-void UserApiImpl::create_users_with_list_input(const std::vector<std::shared_ptr<User>> &user, Pistache::Http::ResponseWriter &response) {
+void UserApiImpl::create_users_with_list_input(const std::vector<User> &user, Pistache::Http::ResponseWriter &response) {
     response.send(Pistache::Http::Code::Ok, "Do some magic\n");
 }
 void UserApiImpl::delete_user(const std::string &username, Pistache::Http::ResponseWriter &response) {
@@ -38,7 +38,7 @@ void UserApiImpl::delete_user(const std::string &username, Pistache::Http::Respo
 void UserApiImpl::get_user_by_name(const std::string &username, Pistache::Http::ResponseWriter &response) {
     response.send(Pistache::Http::Code::Ok, "Do some magic\n");
 }
-void UserApiImpl::login_user(const Optional<std::string> &username, const Optional<std::string> &password, Pistache::Http::ResponseWriter &response) {
+void UserApiImpl::login_user(const Pistache::Optional<std::string> &username, const Pistache::Optional<std::string> &password, Pistache::Http::ResponseWriter &response) {
     response.send(Pistache::Http::Code::Ok, "Do some magic\n");
 }
 void UserApiImpl::logout_user(Pistache::Http::ResponseWriter &response) {
diff --git a/samples/server/petstore/cpp-pistache/impl/UserApiImpl.h b/samples/server/petstore/cpp-pistache/impl/UserApiImpl.h
index 1569be6b1d4..e719edba141 100644
--- a/samples/server/petstore/cpp-pistache/impl/UserApiImpl.h
+++ b/samples/server/petstore/cpp-pistache/impl/UserApiImpl.h
@@ -27,6 +27,8 @@
 
 #include <UserApi.h>
 
+#include <pistache/optional.h>
+
 #include "User.h"
 #include <string>
 #include <vector>
@@ -44,11 +46,11 @@ public:
     ~UserApiImpl() { };
 
     void create_user(const std::shared_ptr<User> &user, Pistache::Http::ResponseWriter &response);
-    void create_users_with_array_input(const std::vector<std::shared_ptr<User>> &user, Pistache::Http::ResponseWriter &response);
-    void create_users_with_list_input(const std::vector<std::shared_ptr<User>> &user, Pistache::Http::ResponseWriter &response);
+    void create_users_with_array_input(const std::vector<User> &user, Pistache::Http::ResponseWriter &response);
+    void create_users_with_list_input(const std::vector<User> &user, Pistache::Http::ResponseWriter &response);
     void delete_user(const std::string &username, Pistache::Http::ResponseWriter &response);
     void get_user_by_name(const std::string &username, Pistache::Http::ResponseWriter &response);
-    void login_user(const Optional<std::string> &username, const Optional<std::string> &password, Pistache::Http::ResponseWriter &response);
+    void login_user(const Pistache::Optional<std::string> &username, const Pistache::Optional<std::string> &password, Pistache::Http::ResponseWriter &response);
     void logout_user(Pistache::Http::ResponseWriter &response);
     void update_user(const std::string &username, const std::shared_ptr<User> &user, Pistache::Http::ResponseWriter &response);
 
diff --git a/samples/server/petstore/cpp-pistache/model/ApiResponse.cpp b/samples/server/petstore/cpp-pistache/model/ApiResponse.cpp
index 5cab25713d9..bb07343a1b4 100644
--- a/samples/server/petstore/cpp-pistache/model/ApiResponse.cpp
+++ b/samples/server/petstore/cpp-pistache/model/ApiResponse.cpp
@@ -83,7 +83,7 @@ int32_t ApiResponse::getCode() const
 {
     return m_Code;
 }
-void ApiResponse::setCode(int32_t value)
+void ApiResponse::setCode(int32_t const value)
 {
     m_Code = value;
     m_CodeIsSet = true;
@@ -100,7 +100,7 @@ std::string ApiResponse::getType() const
 {
     return m_Type;
 }
-void ApiResponse::setType(std::string value)
+void ApiResponse::setType(std::string const& value)
 {
     m_Type = value;
     m_TypeIsSet = true;
@@ -117,7 +117,7 @@ std::string ApiResponse::getMessage() const
 {
     return m_Message;
 }
-void ApiResponse::setMessage(std::string value)
+void ApiResponse::setMessage(std::string const& value)
 {
     m_Message = value;
     m_MessageIsSet = true;
diff --git a/samples/server/petstore/cpp-pistache/model/ApiResponse.h b/samples/server/petstore/cpp-pistache/model/ApiResponse.h
index dbdbf29b826..51c96e3838c 100644
--- a/samples/server/petstore/cpp-pistache/model/ApiResponse.h
+++ b/samples/server/petstore/cpp-pistache/model/ApiResponse.h
@@ -53,21 +53,21 @@ public:
     /// 
     /// </summary>
     int32_t getCode() const;
-    void setCode(int32_t value);
+    void setCode(int32_t const value);
     bool codeIsSet() const;
     void unsetCode();
     /// <summary>
     /// 
     /// </summary>
     std::string getType() const;
-    void setType(std::string value);
+    void setType(std::string const& value);
     bool typeIsSet() const;
     void unsetType();
     /// <summary>
     /// 
     /// </summary>
     std::string getMessage() const;
-    void setMessage(std::string value);
+    void setMessage(std::string const& value);
     bool messageIsSet() const;
     void unsetMessage();
 
diff --git a/samples/server/petstore/cpp-pistache/model/Category.cpp b/samples/server/petstore/cpp-pistache/model/Category.cpp
index d528f343d7e..a1d24fdab57 100644
--- a/samples/server/petstore/cpp-pistache/model/Category.cpp
+++ b/samples/server/petstore/cpp-pistache/model/Category.cpp
@@ -72,7 +72,7 @@ int64_t Category::getId() const
 {
     return m_Id;
 }
-void Category::setId(int64_t value)
+void Category::setId(int64_t const value)
 {
     m_Id = value;
     m_IdIsSet = true;
@@ -89,7 +89,7 @@ std::string Category::getName() const
 {
     return m_Name;
 }
-void Category::setName(std::string value)
+void Category::setName(std::string const& value)
 {
     m_Name = value;
     m_NameIsSet = true;
diff --git a/samples/server/petstore/cpp-pistache/model/Category.h b/samples/server/petstore/cpp-pistache/model/Category.h
index 6e3885e2d73..19b951a44e7 100644
--- a/samples/server/petstore/cpp-pistache/model/Category.h
+++ b/samples/server/petstore/cpp-pistache/model/Category.h
@@ -53,14 +53,14 @@ public:
     /// 
     /// </summary>
     int64_t getId() const;
-    void setId(int64_t value);
+    void setId(int64_t const value);
     bool idIsSet() const;
     void unsetId();
     /// <summary>
     /// 
     /// </summary>
     std::string getName() const;
-    void setName(std::string value);
+    void setName(std::string const& value);
     bool nameIsSet() const;
     void unsetName();
 
diff --git a/samples/server/petstore/cpp-pistache/model/ModelBase.cpp b/samples/server/petstore/cpp-pistache/model/ModelBase.cpp
index dca7f7198ff..d8c2437c6ff 100644
--- a/samples/server/petstore/cpp-pistache/model/ModelBase.cpp
+++ b/samples/server/petstore/cpp-pistache/model/ModelBase.cpp
@@ -23,41 +23,41 @@ ModelBase::~ModelBase()
 {
 }
 
-std::string ModelBase::toJson( const std::string& value )
+std::string ModelBase::toJson( std::string const& value )
 {
     return value;
 }
 
-std::string ModelBase::toJson( const std::time_t& value )
+std::string ModelBase::toJson( std::time_t const& value )
 {
     char buf[sizeof "2011-10-08T07:07:09Z"];
     strftime(buf, sizeof buf, "%FT%TZ", gmtime(&value));
     return buf;
 }
 
-int32_t ModelBase::toJson( int32_t value )
+int32_t ModelBase::toJson( int32_t const value )
 {
     return value;
 }
 
-int64_t ModelBase::toJson( int64_t value )
+int64_t ModelBase::toJson( int64_t const value )
 {
     return value;
 }
 
-double ModelBase::toJson( double value )
+double ModelBase::toJson( double const value )
 {
     return value;
 }
 
-bool ModelBase::toJson( bool value )
+bool ModelBase::toJson( bool const value )
 {
     return value;
 }
 
-nlohmann::json ModelBase::toJson( std::shared_ptr<ModelBase> content )
+nlohmann::json ModelBase::toJson(ModelBase content )
 {
-    return content.get() ? content->toJson() : nlohmann::json();
+    return content.toJson();
 }
 
 }
diff --git a/samples/server/petstore/cpp-pistache/model/ModelBase.h b/samples/server/petstore/cpp-pistache/model/ModelBase.h
index 30918431987..6b5589472f0 100644
--- a/samples/server/petstore/cpp-pistache/model/ModelBase.h
+++ b/samples/server/petstore/cpp-pistache/model/ModelBase.h
@@ -39,13 +39,13 @@ public:
     virtual nlohmann::json toJson() const = 0;
     virtual void fromJson(nlohmann::json& json) = 0;
 
-    static std::string toJson( const std::string& value );
-    static std::string toJson( const std::time_t& value );
-    static int32_t toJson( int32_t value );
-    static int64_t toJson( int64_t value );
-    static double toJson( double value );
-    static bool toJson( bool value );
-    static nlohmann::json toJson( std::shared_ptr<ModelBase> content );
+    static std::string toJson(  std::string const& value );
+    static std::string toJson(  std::time_t const& value );
+    static int32_t toJson( int32_t const value );
+    static int64_t toJson( int64_t const value );
+    static double toJson( double const value );
+    static bool toJson( bool const value );
+    static nlohmann::json toJson(ModelBase const& content );
 
 };
 
diff --git a/samples/server/petstore/cpp-pistache/model/Order.cpp b/samples/server/petstore/cpp-pistache/model/Order.cpp
index 712705e313e..fb3fde19d3a 100644
--- a/samples/server/petstore/cpp-pistache/model/Order.cpp
+++ b/samples/server/petstore/cpp-pistache/model/Order.cpp
@@ -113,7 +113,7 @@ int64_t Order::getId() const
 {
     return m_Id;
 }
-void Order::setId(int64_t value)
+void Order::setId(int64_t const value)
 {
     m_Id = value;
     m_IdIsSet = true;
@@ -130,7 +130,7 @@ int64_t Order::getPetId() const
 {
     return m_PetId;
 }
-void Order::setPetId(int64_t value)
+void Order::setPetId(int64_t const value)
 {
     m_PetId = value;
     m_PetIdIsSet = true;
@@ -147,7 +147,7 @@ int32_t Order::getQuantity() const
 {
     return m_Quantity;
 }
-void Order::setQuantity(int32_t value)
+void Order::setQuantity(int32_t const value)
 {
     m_Quantity = value;
     m_QuantityIsSet = true;
@@ -164,7 +164,7 @@ std::string Order::getShipDate() const
 {
     return m_ShipDate;
 }
-void Order::setShipDate(std::string value)
+void Order::setShipDate(std::string const& value)
 {
     m_ShipDate = value;
     m_ShipDateIsSet = true;
@@ -181,7 +181,7 @@ std::string Order::getStatus() const
 {
     return m_Status;
 }
-void Order::setStatus(std::string value)
+void Order::setStatus(std::string const& value)
 {
     m_Status = value;
     m_StatusIsSet = true;
@@ -198,7 +198,7 @@ bool Order::isComplete() const
 {
     return m_Complete;
 }
-void Order::setComplete(bool value)
+void Order::setComplete(bool const value)
 {
     m_Complete = value;
     m_CompleteIsSet = true;
diff --git a/samples/server/petstore/cpp-pistache/model/Order.h b/samples/server/petstore/cpp-pistache/model/Order.h
index bc577671554..548f9de0614 100644
--- a/samples/server/petstore/cpp-pistache/model/Order.h
+++ b/samples/server/petstore/cpp-pistache/model/Order.h
@@ -53,42 +53,42 @@ public:
     /// 
     /// </summary>
     int64_t getId() const;
-    void setId(int64_t value);
+    void setId(int64_t const value);
     bool idIsSet() const;
     void unsetId();
     /// <summary>
     /// 
     /// </summary>
     int64_t getPetId() const;
-    void setPetId(int64_t value);
+    void setPetId(int64_t const value);
     bool petIdIsSet() const;
     void unsetPetId();
     /// <summary>
     /// 
     /// </summary>
     int32_t getQuantity() const;
-    void setQuantity(int32_t value);
+    void setQuantity(int32_t const value);
     bool quantityIsSet() const;
     void unsetQuantity();
     /// <summary>
     /// 
     /// </summary>
     std::string getShipDate() const;
-    void setShipDate(std::string value);
+    void setShipDate(std::string const& value);
     bool shipDateIsSet() const;
     void unsetShipDate();
     /// <summary>
     /// Order Status
     /// </summary>
     std::string getStatus() const;
-    void setStatus(std::string value);
+    void setStatus(std::string const& value);
     bool statusIsSet() const;
     void unsetStatus();
     /// <summary>
     /// 
     /// </summary>
     bool isComplete() const;
-    void setComplete(bool value);
+    void setComplete(bool const value);
     bool completeIsSet() const;
     void unsetComplete();
 
diff --git a/samples/server/petstore/cpp-pistache/model/Pet.cpp b/samples/server/petstore/cpp-pistache/model/Pet.cpp
index 58447515d42..2c200a8db2c 100644
--- a/samples/server/petstore/cpp-pistache/model/Pet.cpp
+++ b/samples/server/petstore/cpp-pistache/model/Pet.cpp
@@ -91,8 +91,8 @@ void Pet::fromJson(nlohmann::json& val)
     {
         if(!val["category"].is_null())
         {
-            std::shared_ptr<Category> newItem(new Category());
-            newItem->fromJson(val["category"]);
+            Category newItem(Category());
+            newItem.fromJson(val["category"]);
             setCategory( newItem );
         }
         
@@ -117,12 +117,12 @@ void Pet::fromJson(nlohmann::json& val)
             
             if(item.is_null())
             {
-                m_Tags.push_back( std::shared_ptr<Tag>(nullptr) );
+                m_Tags.push_back( Tag(nullptr) );
             }
             else
             {
-                std::shared_ptr<Tag> newItem(new Tag());
-                newItem->fromJson(item);
+                Tag newItem(Tag());
+                newItem.fromJson(item);
                 m_Tags.push_back( newItem );
             }
             
@@ -142,7 +142,7 @@ int64_t Pet::getId() const
 {
     return m_Id;
 }
-void Pet::setId(int64_t value)
+void Pet::setId(int64_t const value)
 {
     m_Id = value;
     m_IdIsSet = true;
@@ -155,11 +155,11 @@ void Pet::unsetId()
 {
     m_IdIsSet = false;
 }
-std::shared_ptr<Category> Pet::getCategory() const
+Category Pet::getCategory() const
 {
     return m_Category;
 }
-void Pet::setCategory(std::shared_ptr<Category> value)
+void Pet::setCategory(Category const& value)
 {
     m_Category = value;
     m_CategoryIsSet = true;
@@ -176,7 +176,7 @@ std::string Pet::getName() const
 {
     return m_Name;
 }
-void Pet::setName(std::string value)
+void Pet::setName(std::string const& value)
 {
     m_Name = value;
     
@@ -185,7 +185,7 @@ std::vector<std::string>& Pet::getPhotoUrls()
 {
     return m_PhotoUrls;
 }
-std::vector<std::shared_ptr<Tag>>& Pet::getTags()
+std::vector<Tag>& Pet::getTags()
 {
     return m_Tags;
 }
@@ -201,7 +201,7 @@ std::string Pet::getStatus() const
 {
     return m_Status;
 }
-void Pet::setStatus(std::string value)
+void Pet::setStatus(std::string const& value)
 {
     m_Status = value;
     m_StatusIsSet = true;
diff --git a/samples/server/petstore/cpp-pistache/model/Pet.h b/samples/server/petstore/cpp-pistache/model/Pet.h
index d0d84c4aeac..4117dcf468d 100644
--- a/samples/server/petstore/cpp-pistache/model/Pet.h
+++ b/samples/server/petstore/cpp-pistache/model/Pet.h
@@ -56,21 +56,21 @@ public:
     /// 
     /// </summary>
     int64_t getId() const;
-    void setId(int64_t value);
+    void setId(int64_t const value);
     bool idIsSet() const;
     void unsetId();
     /// <summary>
     /// 
     /// </summary>
-    std::shared_ptr<Category> getCategory() const;
-    void setCategory(std::shared_ptr<Category> value);
+    Category getCategory() const;
+    void setCategory(Category const& value);
     bool categoryIsSet() const;
     void unsetCategory();
     /// <summary>
     /// 
     /// </summary>
     std::string getName() const;
-    void setName(std::string value);
+    void setName(std::string const& value);
         /// <summary>
     /// 
     /// </summary>
@@ -78,27 +78,27 @@ public:
         /// <summary>
     /// 
     /// </summary>
-    std::vector<std::shared_ptr<Tag>>& getTags();
+    std::vector<Tag>& getTags();
     bool tagsIsSet() const;
     void unsetTags();
     /// <summary>
     /// pet status in the store
     /// </summary>
     std::string getStatus() const;
-    void setStatus(std::string value);
+    void setStatus(std::string const& value);
     bool statusIsSet() const;
     void unsetStatus();
 
 protected:
     int64_t m_Id;
     bool m_IdIsSet;
-    std::shared_ptr<Category> m_Category;
+    Category m_Category;
     bool m_CategoryIsSet;
     std::string m_Name;
 
     std::vector<std::string> m_PhotoUrls;
 
-    std::vector<std::shared_ptr<Tag>> m_Tags;
+    std::vector<Tag> m_Tags;
     bool m_TagsIsSet;
     std::string m_Status;
     bool m_StatusIsSet;
diff --git a/samples/server/petstore/cpp-pistache/model/Tag.cpp b/samples/server/petstore/cpp-pistache/model/Tag.cpp
index 9091c15cfd9..1cbc344ba52 100644
--- a/samples/server/petstore/cpp-pistache/model/Tag.cpp
+++ b/samples/server/petstore/cpp-pistache/model/Tag.cpp
@@ -72,7 +72,7 @@ int64_t Tag::getId() const
 {
     return m_Id;
 }
-void Tag::setId(int64_t value)
+void Tag::setId(int64_t const value)
 {
     m_Id = value;
     m_IdIsSet = true;
@@ -89,7 +89,7 @@ std::string Tag::getName() const
 {
     return m_Name;
 }
-void Tag::setName(std::string value)
+void Tag::setName(std::string const& value)
 {
     m_Name = value;
     m_NameIsSet = true;
diff --git a/samples/server/petstore/cpp-pistache/model/Tag.h b/samples/server/petstore/cpp-pistache/model/Tag.h
index 08a4fec456d..1b5d79e31c9 100644
--- a/samples/server/petstore/cpp-pistache/model/Tag.h
+++ b/samples/server/petstore/cpp-pistache/model/Tag.h
@@ -53,14 +53,14 @@ public:
     /// 
     /// </summary>
     int64_t getId() const;
-    void setId(int64_t value);
+    void setId(int64_t const value);
     bool idIsSet() const;
     void unsetId();
     /// <summary>
     /// 
     /// </summary>
     std::string getName() const;
-    void setName(std::string value);
+    void setName(std::string const& value);
     bool nameIsSet() const;
     void unsetName();
 
diff --git a/samples/server/petstore/cpp-pistache/model/User.cpp b/samples/server/petstore/cpp-pistache/model/User.cpp
index 88e159c196f..e0f4defae3e 100644
--- a/samples/server/petstore/cpp-pistache/model/User.cpp
+++ b/samples/server/petstore/cpp-pistache/model/User.cpp
@@ -137,7 +137,7 @@ int64_t User::getId() const
 {
     return m_Id;
 }
-void User::setId(int64_t value)
+void User::setId(int64_t const value)
 {
     m_Id = value;
     m_IdIsSet = true;
@@ -154,7 +154,7 @@ std::string User::getUsername() const
 {
     return m_Username;
 }
-void User::setUsername(std::string value)
+void User::setUsername(std::string const& value)
 {
     m_Username = value;
     m_UsernameIsSet = true;
@@ -171,7 +171,7 @@ std::string User::getFirstName() const
 {
     return m_FirstName;
 }
-void User::setFirstName(std::string value)
+void User::setFirstName(std::string const& value)
 {
     m_FirstName = value;
     m_FirstNameIsSet = true;
@@ -188,7 +188,7 @@ std::string User::getLastName() const
 {
     return m_LastName;
 }
-void User::setLastName(std::string value)
+void User::setLastName(std::string const& value)
 {
     m_LastName = value;
     m_LastNameIsSet = true;
@@ -205,7 +205,7 @@ std::string User::getEmail() const
 {
     return m_Email;
 }
-void User::setEmail(std::string value)
+void User::setEmail(std::string const& value)
 {
     m_Email = value;
     m_EmailIsSet = true;
@@ -222,7 +222,7 @@ std::string User::getPassword() const
 {
     return m_Password;
 }
-void User::setPassword(std::string value)
+void User::setPassword(std::string const& value)
 {
     m_Password = value;
     m_PasswordIsSet = true;
@@ -239,7 +239,7 @@ std::string User::getPhone() const
 {
     return m_Phone;
 }
-void User::setPhone(std::string value)
+void User::setPhone(std::string const& value)
 {
     m_Phone = value;
     m_PhoneIsSet = true;
@@ -256,7 +256,7 @@ int32_t User::getUserStatus() const
 {
     return m_UserStatus;
 }
-void User::setUserStatus(int32_t value)
+void User::setUserStatus(int32_t const value)
 {
     m_UserStatus = value;
     m_UserStatusIsSet = true;
diff --git a/samples/server/petstore/cpp-pistache/model/User.h b/samples/server/petstore/cpp-pistache/model/User.h
index e8dab49531d..b9a53345866 100644
--- a/samples/server/petstore/cpp-pistache/model/User.h
+++ b/samples/server/petstore/cpp-pistache/model/User.h
@@ -53,56 +53,56 @@ public:
     /// 
     /// </summary>
     int64_t getId() const;
-    void setId(int64_t value);
+    void setId(int64_t const value);
     bool idIsSet() const;
     void unsetId();
     /// <summary>
     /// 
     /// </summary>
     std::string getUsername() const;
-    void setUsername(std::string value);
+    void setUsername(std::string const& value);
     bool usernameIsSet() const;
     void unsetUsername();
     /// <summary>
     /// 
     /// </summary>
     std::string getFirstName() const;
-    void setFirstName(std::string value);
+    void setFirstName(std::string const& value);
     bool firstNameIsSet() const;
     void unsetFirstName();
     /// <summary>
     /// 
     /// </summary>
     std::string getLastName() const;
-    void setLastName(std::string value);
+    void setLastName(std::string const& value);
     bool lastNameIsSet() const;
     void unsetLastName();
     /// <summary>
     /// 
     /// </summary>
     std::string getEmail() const;
-    void setEmail(std::string value);
+    void setEmail(std::string const& value);
     bool emailIsSet() const;
     void unsetEmail();
     /// <summary>
     /// 
     /// </summary>
     std::string getPassword() const;
-    void setPassword(std::string value);
+    void setPassword(std::string const& value);
     bool passwordIsSet() const;
     void unsetPassword();
     /// <summary>
     /// 
     /// </summary>
     std::string getPhone() const;
-    void setPhone(std::string value);
+    void setPhone(std::string const& value);
     bool phoneIsSet() const;
     void unsetPhone();
     /// <summary>
     /// User Status
     /// </summary>
     int32_t getUserStatus() const;
-    void setUserStatus(int32_t value);
+    void setUserStatus(int32_t const value);
     bool userStatusIsSet() const;
     void unsetUserStatus();