[c++ pistache server] Support basic query handling (#943)

Support basic query handling

Add  helpers for primitive de-serialization
Remove warnings due to unneeded commas
Deserialize basic types in queries
Add dependencies chain for external libraries
Fixes wrong parameter passed to API

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppPistacheServerCodegen.java

@@ -47,8 +47,10 @@ public class CppPistacheServerCodegen extends AbstractCppCodegen {
     protected boolean isAddExternalLibs = true;
     public static final String OPTIONAL_EXTERNAL_LIB = "addExternalLibs";
     public static final String OPTIONAL_EXTERNAL_LIB_DESC = "Add the Possibility to fetch and compile external Libraries needed by this Framework.";
+    public static final String HELPERS_PACKAGE_NAME = "helpersPackage";
+    public static final String HELPERS_PACKAGE_NAME_DESC = "Specify the package name to be used for the helpers (e.g. org.openapitools.server.helpers).";
     protected final String PREFIX = "";
-
+    protected String helpersPackage = "";
     @Override
     public CodegenType getTag() {
         return CodegenType.SERVER;
@@ -70,6 +72,7 @@ public class CppPistacheServerCodegen extends AbstractCppCodegen {
             modelNamePrefix = PREFIX;
         }
 
+        helpersPackage = "org.openapitools.server.helpers";
         apiPackage = "org.openapitools.server.api";
         modelPackage = "org.openapitools.server.model";
 
@@ -86,11 +89,14 @@ public class CppPistacheServerCodegen extends AbstractCppCodegen {
 
         cliOptions.clear();
         addSwitch(OPTIONAL_EXTERNAL_LIB, OPTIONAL_EXTERNAL_LIB_DESC, this.isAddExternalLibs);
+        addOption(HELPERS_PACKAGE_NAME, HELPERS_PACKAGE_NAME_DESC, this.helpersPackage);
 
         reservedWords = new HashSet<>();
 
         supportingFiles.add(new SupportingFile("modelbase-header.mustache", "model", modelNamePrefix + "ModelBase.h"));
         supportingFiles.add(new SupportingFile("modelbase-source.mustache", "model", modelNamePrefix + "ModelBase.cpp"));
+        supportingFiles.add(new SupportingFile("helpers-header.mustache", "model", modelNamePrefix + "Helpers.h"));
+        supportingFiles.add(new SupportingFile("helpers-source.mustache", "model", modelNamePrefix + "Helpers.cpp"));
         supportingFiles.add(new SupportingFile("cmake.mustache", "", "CMakeLists.txt"));
         supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
 
@@ -123,18 +129,26 @@ public class CppPistacheServerCodegen extends AbstractCppCodegen {
     @Override
     public void processOpts() {
         super.processOpts();
+        if (additionalProperties.containsKey(HELPERS_PACKAGE_NAME)) {
+            helpersPackage = (String) additionalProperties.get(HELPERS_PACKAGE_NAME);
+        }
         if (additionalProperties.containsKey("modelNamePrefix")) {
             additionalProperties().put("prefix", modelNamePrefix);
             supportingFiles.clear();
             supportingFiles.add(new SupportingFile("modelbase-header.mustache", "model", modelNamePrefix + "ModelBase.h"));
             supportingFiles.add(new SupportingFile("modelbase-source.mustache", "model", modelNamePrefix + "ModelBase.cpp"));
+            supportingFiles.add(new SupportingFile("helpers-header.mustache", "model", modelNamePrefix + "Helpers.h"));
+            supportingFiles.add(new SupportingFile("helpers-source.mustache", "model", modelNamePrefix + "Helpers.cpp"));
             supportingFiles.add(new SupportingFile("cmake.mustache", "", "CMakeLists.txt"));
             supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
         }
         additionalProperties.put("modelNamespaceDeclarations", modelPackage.split("\\."));
         additionalProperties.put("modelNamespace", modelPackage.replaceAll("\\.", "::"));
         additionalProperties.put("apiNamespaceDeclarations", apiPackage.split("\\."));
-        additionalProperties.put("apiNamespace", apiPackage.replaceAll("\\.", "::"));   
+        additionalProperties.put("apiNamespace", apiPackage.replaceAll("\\.", "::"));  
+        additionalProperties.put("helpersNamespaceDeclarations", helpersPackage.split("\\."));
+        additionalProperties.put("helpersNamespace", helpersPackage.replaceAll("\\.", "::")); 
+                
         if (additionalProperties.containsKey(OPTIONAL_EXTERNAL_LIB)) {
             setAddExternalLibs(convertPropertyToBooleanAndWriteBack(OPTIONAL_EXTERNAL_LIB));
         } else {
@@ -236,7 +250,7 @@ public class CppPistacheServerCodegen extends AbstractCppCodegen {
                     if (param.isPrimitiveType) {
                         param.dataType = "Pistache::Optional<" + param.dataType + ">";
                     } else {
-                        param.dataType = "Pistache::Optional<" + param.baseType + ">";
+                        param.dataType = "Pistache::Optional<" + param.dataType + ">";
                         param.baseType = "Pistache::Optional<" + param.baseType + ">";
                     }
                 }

modules/openapi-generator/src/main/resources/cpp-pistache-server/api-header.mustache

@@ -29,7 +29,7 @@ using namespace {{modelNamespace}};{{/hasModelImport}}
 class {{declspec}} {{classname}} {
 public:
     {{classname}}(Pistache::Address addr);
-    virtual ~{{classname}}() {};
+    virtual ~{{classname}}() {}
     void init(size_t thr);
     void start();
     void shutdown();

modules/openapi-generator/src/main/resources/cpp-pistache-server/api-impl-header.mustache

@@ -32,7 +32,7 @@ using namespace {{modelNamespace}};{{/hasModelImport}}
 class {{classname}}Impl : public {{apiNamespace}}::{{classname}} {
 public:
     {{classname}}Impl(Pistache::Address addr);
-    ~{{classname}}Impl() { };
+    ~{{classname}}Impl() {}
 
     {{#operation}}
     {{#vendorExtensions.x-codegen-pistache-isParsingSupported}}

modules/openapi-generator/src/main/resources/cpp-pistache-server/api-source.mustache

@@ -2,11 +2,13 @@
 {{#operations}}
 
 #include "{{classname}}.h"
+#include "{{prefix}}Helpers.h"
 
 {{#apiNamespaceDeclarations}}
 namespace {{this}} {
 {{/apiNamespaceDeclarations}}
 
+using namespace {{helpersNamespace}};
 {{#hasModelImport}}
 using namespace {{modelNamespace}};{{/hasModelImport}}
 
@@ -62,7 +64,14 @@ void {{classname}}::{{operationIdSnakeCase}}_handler(const Pistache::Rest::Reque
     {{/hasBodyParam}}{{#hasQueryParams}}
     // Getting the query params
     {{#queryParams}}
-    auto {{paramName}} = request.query().get("{{baseName}}");
+    auto {{paramName}}Query = request.query().get("{{baseName}}");
+    Pistache::Optional<{{^isContainer}}{{dataType}}{{/isContainer}}{{#isListContainer}}std::vector<{{items.baseType}}>{{/isListContainer}}> {{paramName}};
+    if(!{{paramName}}Query.isEmpty()){
+        {{^isContainer}}{{dataType}}{{/isContainer}}{{#isListContainer}}std::vector<{{items.baseType}}>{{/isListContainer}} value;
+        if(fromStringValue({{paramName}}Query.get(), value)){
+            {{paramName}} = Pistache::Some(value);
+        }
+    }
     {{/queryParams}}
     {{/hasQueryParams}}{{#hasHeaderParams}}
     // Getting the header params

modules/openapi-generator/src/main/resources/cpp-pistache-server/cmake.mustache

@@ -56,6 +56,9 @@ set(<%classnameSnakeUpperCase%>_SERVER_SOURCES
 <%#operations%>
 add_executable(<%classnameSnakeLowerCase%>_server
 ${<%classnameSnakeUpperCase%>_SERVER_SOURCES})
+<%#addExternalLibs%>
+add_dependencies(<%classnameSnakeLowerCase%>_server PISTACHE NLOHMANN)
+<%/addExternalLibs%>
 <%/operations%>
 <%/apiInfo.apis%>
 

modules/openapi-generator/src/main/resources/cpp-pistache-server/helpers-header.mustache

@@ -0,0 +1,64 @@
+{{>licenseInfo}}
+/*
+ * {{prefix}}Helpers.h
+ *
+ * This is the helper class for models and primitives
+ */
+
+#ifndef {{prefix}}Helpers_H_
+#define {{prefix}}Helpers_H_
+
+#include <ctime>
+#include <string>
+#include <sstream>
+#include <vector>
+#include <map>
+
+{{#helpersNamespaceDeclarations}}
+namespace {{this}} {
+{{/helpersNamespaceDeclarations}}
+
+    std::string toStringValue(const std::string &value);
+    std::string toStringValue(const int32_t &value);
+    std::string toStringValue(const int64_t &value);
+    std::string toStringValue(const bool &value);
+    std::string toStringValue(const float &value);
+    std::string toStringValue(const double &value);
+
+    bool fromStringValue(const std::string &inStr, std::string &value);
+    bool fromStringValue(const std::string &inStr, int32_t &value);
+    bool fromStringValue(const std::string &inStr, int64_t &value);
+    bool fromStringValue(const std::string &inStr, bool &value);
+    bool fromStringValue(const std::string &inStr, float &value);
+    bool fromStringValue(const std::string &inStr, double &value);
+    template<typename T>
+    bool fromStringValue(const std::vector<std::string> &inStr, std::vector<T> &value){
+        try{
+            for(auto & item : inStr){
+                T itemValue;
+                if(fromStringValue(item, itemValue)){
+                    value.push_back(itemValue);
+                }
+            }
+        }
+        catch(...){
+            return false;
+        }
+        return value.size() > 0;
+    }
+    template<typename T>
+    bool fromStringValue(const std::string &inStr, std::vector<T> &value, char separator = ','){
+        std::vector<std::string> inStrings;
+        std::istringstream f(inStr);
+        std::string s;
+        while (std::getline(f, s, separator)) {
+            inStrings.push_back(s);
+        }
+        return fromStringValue(inStrings, value);
+    }
+
+{{#helpersNamespaceDeclarations}}
+}
+{{/helpersNamespaceDeclarations}}
+
+#endif // {{prefix}}Helpers_H_

modules/openapi-generator/src/main/resources/cpp-pistache-server/helpers-source.mustache

@@ -0,0 +1,86 @@
+{{>licenseInfo}}
+#include "{{prefix}}Helpers.h"
+
+{{#helpersNamespaceDeclarations}}
+namespace {{this}} {
+{{/helpersNamespaceDeclarations}}
+
+
+std::string toStringValue(const std::string &value){
+    return std::string(value);
+}
+
+std::string toStringValue(const int32_t &value){
+    return std::to_string(value);
+}
+
+std::string toStringValue(const int64_t &value){
+    return std::to_string(value);
+}
+
+std::string toStringValue(const bool &value){
+    return value?std::string("true"):std::string("false");
+}
+
+std::string toStringValue(const float &value){
+    return std::to_string(value);
+}
+
+std::string toStringValue(const double &value){
+    return std::to_string(value);
+}
+
+bool fromStringValue(const std::string &inStr, std::string &value){
+    value = std::string(inStr);
+    return true;
+}
+
+bool fromStringValue(const std::string &inStr, int32_t &value){
+    try {
+        value = std::stoi( inStr );
+    }
+    catch (const std::invalid_argument) {
+        return false;
+    }
+    return true;
+}
+
+bool fromStringValue(const std::string &inStr, int64_t &value){
+    try {
+        value = std::stol( inStr );
+    }
+    catch (const std::invalid_argument) {
+        return false;
+    }
+    return true;
+}
+
+bool fromStringValue(const std::string &inStr, bool &value){
+    bool result = true;
+    inStr == "true"?value = true: inStr == "false"?value = false: result = false;
+    return result;
+}
+
+bool fromStringValue(const std::string &inStr, float &value){
+    try {
+        value = std::stof( inStr );
+    }
+    catch (const std::invalid_argument) {
+        return false;
+    }
+    return true;
+}
+
+bool fromStringValue(const std::string &inStr, double &value){
+    try {
+        value = std::stod( inStr );
+    }
+    catch (const std::invalid_argument) {
+        return false;
+    }
+    return true;
+}
+
+{{#helpersNamespaceDeclarations}}
+}
+{{/helpersNamespaceDeclarations}}

modules/openapi-generator/src/main/resources/cpp-pistache-server/model-source.mustache

@@ -95,15 +95,15 @@ void {{classname}}::fromJson(nlohmann::json& val)
     }
     {{/isListContainer}}{{^isListContainer}}{{^isPrimitiveType}}{{^required}}if(val.find("{{baseName}}") != val.end())
     {
-        {{#isString}}{{setter}}(val.at("{{baseName}}"));{{/isString}}{{#isByteArray}}{{setter}}(val.at("{{baseName}}"));
+        {{#isString}}{{setter}}(val.at("{{baseName}}"));{{/isString}}{{#isByteArray}}{{setter}}(val.at("{{baseName}}"));{{/isByteArray}}{{#isBinary}}{{setter}}(val.at("{{baseName}}"));
-        {{/isByteArray}}{{^isString}}{{#isDateTime}}{{setter}}(val.at("{{baseName}}"));
+        {{/isBinary}}{{^isString}}{{#isDateTime}}{{setter}}(val.at("{{baseName}}"));
-        {{/isDateTime}}{{^isDateTime}}{{^isByteArray}}if(!val["{{baseName}}"].is_null())
+        {{/isDateTime}}{{^isDateTime}}{{^isByteArray}}{{^isBinary}}if(!val["{{baseName}}"].is_null())
         {
             {{{dataType}}} newItem;
             newItem.fromJson(val["{{baseName}}"]);
             {{setter}}( newItem );
         }
-        {{/isByteArray}}{{/isDateTime}}{{/isString}}
+        {{/isBinary}}{{/isByteArray}}{{/isDateTime}}{{/isString}}
     }
     {{/required}}{{#required}}{{#isString}}{{setter}}(val.at("{{baseName}}"));
     {{/isString}}{{^isString}}{{#isDateTime}}{{setter}}(val.at("{{baseName}}"));

samples/server/petstore/cpp-pistache/CMakeLists.txt

@@ -63,10 +63,13 @@ UserApiMainServer.cpp
 
 add_executable(pet_api_server
 ${PET_API_SERVER_SOURCES})
+add_dependencies(pet_api_server PISTACHE NLOHMANN)
 add_executable(store_api_server
 ${STORE_API_SERVER_SOURCES})
+add_dependencies(store_api_server PISTACHE NLOHMANN)
 add_executable(user_api_server
 ${USER_API_SERVER_SOURCES})
+add_dependencies(user_api_server PISTACHE NLOHMANN)
 
 target_link_libraries(pet_api_server pistache pthread)
 target_link_libraries(store_api_server pistache pthread)

samples/server/petstore/cpp-pistache/api/PetApi.cpp

@@ -11,12 +11,14 @@
 */
 
 #include "PetApi.h"
+#include "Helpers.h"
 
 namespace org {
 namespace openapitools {
 namespace server {
 namespace api {
 
+using namespace org::openapitools::server::helpers;
 using namespace org::openapitools::server::model;
 
 PetApi::PetApi(Pistache::Address addr)
@@ -94,7 +96,14 @@ void PetApi::delete_pet_handler(const Pistache::Rest::Request &request, Pistache
 void PetApi::find_pets_by_status_handler(const Pistache::Rest::Request &request, Pistache::Http::ResponseWriter response) {
 
     // Getting the query params
-    auto status = request.query().get("status");
+    auto statusQuery = request.query().get("status");
+    Pistache::Optional<std::vector<std::string>> status;
+    if(!statusQuery.isEmpty()){
+        std::vector<std::string> value;
+        if(fromStringValue(statusQuery.get(), value)){
+            status = Pistache::Some(value);
+        }
+    }
     
     try {
       this->find_pets_by_status(status, response);
@@ -108,7 +117,14 @@ void PetApi::find_pets_by_status_handler(const Pistache::Rest::Request &request,
 void PetApi::find_pets_by_tags_handler(const Pistache::Rest::Request &request, Pistache::Http::ResponseWriter response) {
 
     // Getting the query params
-    auto tags = request.query().get("tags");
+    auto tagsQuery = request.query().get("tags");
+    Pistache::Optional<std::vector<std::string>> tags;
+    if(!tagsQuery.isEmpty()){
+        std::vector<std::string> value;
+        if(fromStringValue(tagsQuery.get(), value)){
+            tags = Pistache::Some(value);
+        }
+    }
     
     try {
       this->find_pets_by_tags(tags, response);

samples/server/petstore/cpp-pistache/api/PetApi.h

@@ -40,7 +40,7 @@ using namespace org::openapitools::server::model;
 class  PetApi {
 public:
     PetApi(Pistache::Address addr);
-    virtual ~PetApi() {};
+    virtual ~PetApi() {}
     void init(size_t thr);
     void start();
     void shutdown();
@@ -90,7 +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 Pistache::Optional<std::string> &status, Pistache::Http::ResponseWriter &response) = 0;
+    virtual void find_pets_by_status(const Pistache::Optional<std::vector<std::string>> &status, Pistache::Http::ResponseWriter &response) = 0;
 
     /// <summary>
     /// Finds Pets by tags
@@ -99,7 +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 Pistache::Optional<std::string> &tags, Pistache::Http::ResponseWriter &response) = 0;
+    virtual void find_pets_by_tags(const Pistache::Optional<std::vector<std::string>> &tags, Pistache::Http::ResponseWriter &response) = 0;
 
     /// <summary>
     /// Find pet by ID

samples/server/petstore/cpp-pistache/api/StoreApi.cpp

@@ -11,12 +11,14 @@
 */
 
 #include "StoreApi.h"
+#include "Helpers.h"
 
 namespace org {
 namespace openapitools {
 namespace server {
 namespace api {
 
+using namespace org::openapitools::server::helpers;
 using namespace org::openapitools::server::model;
 
 StoreApi::StoreApi(Pistache::Address addr)

samples/server/petstore/cpp-pistache/api/StoreApi.h

@@ -40,7 +40,7 @@ using namespace org::openapitools::server::model;
 class  StoreApi {
 public:
     StoreApi(Pistache::Address addr);
-    virtual ~StoreApi() {};
+    virtual ~StoreApi() {}
     void init(size_t thr);
     void start();
     void shutdown();

samples/server/petstore/cpp-pistache/api/UserApi.cpp

@@ -11,12 +11,14 @@
 */
 
 #include "UserApi.h"
+#include "Helpers.h"
 
 namespace org {
 namespace openapitools {
 namespace server {
 namespace api {
 
+using namespace org::openapitools::server::helpers;
 using namespace org::openapitools::server::model;
 
 UserApi::UserApi(Pistache::Address addr)
@@ -136,8 +138,22 @@ void UserApi::get_user_by_name_handler(const Pistache::Rest::Request &request, P
 void UserApi::login_user_handler(const Pistache::Rest::Request &request, Pistache::Http::ResponseWriter response) {
 
     // Getting the query params
-    auto username = request.query().get("username");
+    auto usernameQuery = request.query().get("username");
-    auto password = request.query().get("password");
+    Pistache::Optional<std::string> username;
+    if(!usernameQuery.isEmpty()){
+        std::string value;
+        if(fromStringValue(usernameQuery.get(), value)){
+            username = Pistache::Some(value);
+        }
+    }
+    auto passwordQuery = request.query().get("password");
+    Pistache::Optional<std::string> password;
+    if(!passwordQuery.isEmpty()){
+        std::string value;
+        if(fromStringValue(passwordQuery.get(), value)){
+            password = Pistache::Some(value);
+        }
+    }
     
     try {
       this->login_user(username, password, response);

samples/server/petstore/cpp-pistache/api/UserApi.h

@@ -40,7 +40,7 @@ using namespace org::openapitools::server::model;
 class  UserApi {
 public:
     UserApi(Pistache::Address addr);
-    virtual ~UserApi() {};
+    virtual ~UserApi() {}
     void init(size_t thr);
     void start();
     void shutdown();

samples/server/petstore/cpp-pistache/impl/PetApiImpl.cpp

@@ -29,10 +29,10 @@ void PetApiImpl::add_pet(const Pet &pet, Pistache::Http::ResponseWriter &respons
 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 Pistache::Optional<std::string> &status, Pistache::Http::ResponseWriter &response) {
+void PetApiImpl::find_pets_by_status(const Pistache::Optional<std::vector<std::string>> &status, Pistache::Http::ResponseWriter &response) {
     response.send(Pistache::Http::Code::Ok, "Do some magic\n");
 }
-void PetApiImpl::find_pets_by_tags(const Pistache::Optional<std::string> &tags, Pistache::Http::ResponseWriter &response) {
+void PetApiImpl::find_pets_by_tags(const Pistache::Optional<std::vector<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) {

samples/server/petstore/cpp-pistache/impl/PetApiImpl.h

@@ -43,12 +43,12 @@ using namespace org::openapitools::server::model;
 class PetApiImpl : public org::openapitools::server::api::PetApi {
 public:
     PetApiImpl(Pistache::Address addr);
-    ~PetApiImpl() { };
+    ~PetApiImpl() {}
 
     void add_pet(const Pet &pet, 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_status(const Pistache::Optional<std::vector<std::string>> &status, Pistache::Http::ResponseWriter &response);
-    void find_pets_by_tags(const Pistache::Optional<std::string> &tags, Pistache::Http::ResponseWriter &response);
+    void find_pets_by_tags(const Pistache::Optional<std::vector<std::string>> &tags, Pistache::Http::ResponseWriter &response);
     void get_pet_by_id(const int64_t &petId, Pistache::Http::ResponseWriter &response);
     void update_pet(const Pet &pet, Pistache::Http::ResponseWriter &response);
     void update_pet_with_form(const Pistache::Rest::Request &request, Pistache::Http::ResponseWriter &response);

samples/server/petstore/cpp-pistache/impl/StoreApiImpl.h

@@ -43,7 +43,7 @@ using namespace org::openapitools::server::model;
 class StoreApiImpl : public org::openapitools::server::api::StoreApi {
 public:
     StoreApiImpl(Pistache::Address addr);
-    ~StoreApiImpl() { };
+    ~StoreApiImpl() {}
 
     void delete_order(const std::string &orderId, Pistache::Http::ResponseWriter &response);
     void get_inventory(Pistache::Http::ResponseWriter &response);

samples/server/petstore/cpp-pistache/impl/UserApiImpl.h

@@ -43,7 +43,7 @@ using namespace org::openapitools::server::model;
 class UserApiImpl : public org::openapitools::server::api::UserApi {
 public:
     UserApiImpl(Pistache::Address addr);
-    ~UserApiImpl() { };
+    ~UserApiImpl() {}
 
     void create_user(const User &user, Pistache::Http::ResponseWriter &response);
     void create_users_with_array_input(const std::vector<User> &user, Pistache::Http::ResponseWriter &response);

samples/server/petstore/cpp-pistache/model/Helpers.cpp

@@ -0,0 +1,98 @@
+/**
+* OpenAPI Petstore
+* This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+*
+* OpenAPI spec version: 1.0.0
+* 
+*
+* NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+* https://openapi-generator.tech
+* Do not edit the class manually.
+*/
+#include "Helpers.h"
+
+namespace org {
+namespace openapitools {
+namespace server {
+namespace helpers {
+
+
+std::string toStringValue(const std::string &value){
+    return std::string(value);
+}
+
+std::string toStringValue(const int32_t &value){
+    return std::to_string(value);
+}
+
+std::string toStringValue(const int64_t &value){
+    return std::to_string(value);
+}
+
+std::string toStringValue(const bool &value){
+    return value?std::string("true"):std::string("false");
+}
+
+std::string toStringValue(const float &value){
+    return std::to_string(value);
+}
+
+std::string toStringValue(const double &value){
+    return std::to_string(value);
+}
+
+bool fromStringValue(const std::string &inStr, std::string &value){
+    value = std::string(inStr);
+    return true;
+}
+
+bool fromStringValue(const std::string &inStr, int32_t &value){
+    try {
+        value = std::stoi( inStr );
+    }
+    catch (const std::invalid_argument) {
+        return false;
+    }
+    return true;
+}
+
+bool fromStringValue(const std::string &inStr, int64_t &value){
+    try {
+        value = std::stol( inStr );
+    }
+    catch (const std::invalid_argument) {
+        return false;
+    }
+    return true;
+}
+
+bool fromStringValue(const std::string &inStr, bool &value){
+    bool result = true;
+    inStr == "true"?value = true: inStr == "false"?value = false: result = false;
+    return result;
+}
+
+bool fromStringValue(const std::string &inStr, float &value){
+    try {
+        value = std::stof( inStr );
+    }
+    catch (const std::invalid_argument) {
+        return false;
+    }
+    return true;
+}
+
+bool fromStringValue(const std::string &inStr, double &value){
+    try {
+        value = std::stod( inStr );
+    }
+    catch (const std::invalid_argument) {
+        return false;
+    }
+    return true;
+}
+
+}
+}
+}
+}

samples/server/petstore/cpp-pistache/model/Helpers.h

@@ -0,0 +1,76 @@
+/**
+* OpenAPI Petstore
+* This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+*
+* OpenAPI spec version: 1.0.0
+* 
+*
+* NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+* https://openapi-generator.tech
+* Do not edit the class manually.
+*/
+/*
+ * Helpers.h
+ *
+ * This is the helper class for models and primitives
+ */
+
+#ifndef Helpers_H_
+#define Helpers_H_
+
+#include <ctime>
+#include <string>
+#include <sstream>
+#include <vector>
+#include <map>
+
+namespace org {
+namespace openapitools {
+namespace server {
+namespace helpers {
+
+    std::string toStringValue(const std::string &value);
+    std::string toStringValue(const int32_t &value);
+    std::string toStringValue(const int64_t &value);
+    std::string toStringValue(const bool &value);
+    std::string toStringValue(const float &value);
+    std::string toStringValue(const double &value);
+
+    bool fromStringValue(const std::string &inStr, std::string &value);
+    bool fromStringValue(const std::string &inStr, int32_t &value);
+    bool fromStringValue(const std::string &inStr, int64_t &value);
+    bool fromStringValue(const std::string &inStr, bool &value);
+    bool fromStringValue(const std::string &inStr, float &value);
+    bool fromStringValue(const std::string &inStr, double &value);
+    template<typename T>
+    bool fromStringValue(const std::vector<std::string> &inStr, std::vector<T> &value){
+        try{
+            for(auto & item : inStr){
+                T itemValue;
+                if(fromStringValue(item, itemValue)){
+                    value.push_back(itemValue);
+                }
+            }
+        }
+        catch(...){
+            return false;
+        }
+        return value.size() > 0;
+    }
+    template<typename T>
+    bool fromStringValue(const std::string &inStr, std::vector<T> &value, char separator = ','){
+        std::vector<std::string> inStrings;
+        std::istringstream f(inStr);
+        std::string s;
+        while (std::getline(f, s, separator)) {
+            inStrings.push_back(s);
+        }
+        return fromStringValue(inStrings, value);
+    }
+
+}
+}
+}
+}
+
+#endif // Helpers_H_