Improvements from branch 3

Branch3:
Resolved include names and generated file names.
Adjusted mustache files and aligned properly.
Added NLOHMANN_DEFINE_TYPE_INTRUSIVE for json serialization and deserialization.

Branch4:
CppHttplibServerCodegen: Support multiple success codes, void return types, and improve success/error type handling

- Added support for multiple success response codes per operation.
- Handled void return types for operations with no response schema.
- Improved logic for collecting and exposing successTypes and errorTypes in vendor extensions.
- Enhanced mapping and template support for distinguishing between primitive, model, and void responses.
- Handled Enums from specification.

Further improvements (branch4)

Author: rajvesh

bin/configs/cpp-httplib-petstore.yaml

@@ -1,6 +1,6 @@
 generatorName: cpp-httplib-server
 outputDir: samples/server/petstore/cpp-httplib-server
-inputSpec: modules/openapi-generator/src/test/resources/3_0/cpp-httplib-server/petstore.yaml
+inputSpec: modules/openapi-generator/src/test/resources/3_0/cpp-httplib-server/petstore.json
 templateDir: modules/openapi-generator/src/main/resources/cpp-httplib-server
 additionalProperties:
   apiNamespace: "petstore::openapi::api"

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

@@ -12,6 +12,7 @@ org.openapitools.codegen.languages.CrystalClientCodegen
 org.openapitools.codegen.languages.CLibcurlClientCodegen
 org.openapitools.codegen.languages.ClojureClientCodegen
 org.openapitools.codegen.languages.ConfluenceWikiCodegen
+org.openapitools.codegen.languages.CppHttplibServerCodegen
 org.openapitools.codegen.languages.CppOatppClientCodegen
 org.openapitools.codegen.languages.CppQtClientCodegen
 org.openapitools.codegen.languages.CppQtQHttpEngineServerCodegen

modules/openapi-generator/src/main/resources/META-INF/services/org.openapitools.codegen.CodegenConfig

@@ -2,13 +2,14 @@
 
 #pragma once
 
+#include <httplib.h>
+{{#includeVariantHeader}}{{{includeVariantHeader}}}{{/includeVariantHeader}}
+{{#includeOptionalHeader}}{{{includeOptionalHeader}}}{{/includeOptionalHeader}}
+
 {{#modelsUsed}}
 #include "models/{{{.}}}.h"
 {{/modelsUsed}}
 
-#include <httplib.h>
-{{#includeVariantHeader}}{{{includeVariantHeader}}}{{/includeVariantHeader}}
-{{#includeOptionalHeader}}{{{includeOptionalHeader}}}{{/includeOptionalHeader}}
 namespace {{apiNamespace}} {
 class {{apiClassnameInPascalCase}} {
 public:
@@ -30,11 +31,13 @@ public:
     */
     struct {{requestType}}
     {
-        {{#requestModel}}std::optional<{{requestModelNamespace}}::{{requestModel}}> m_request;{{/requestModel}}{{^requestModel}}// No Schema Types defined{{/requestModel}}
-        {{#queryParams}}{{{dataType}}} m_{{paramName}};{{/queryParams}}{{^queryParams}}// Query Params not available{{/queryParams}}
-        {{#headerParams}}{{{dataType}}} m_{{paramName}};{{/headerParams}}{{^headerParams}}// Header Params not available{{/headerParams}}
+        {{#requestModel}}
+        std::optional<{{requestModelNamespace}}::{{requestModel}}> m_request; //Request Body{{/requestModel}}{{#queryParams}}
+        {{{dataType}}} m_{{paramName}}; //Query Params{{/queryParams}}{{#headerParams}}
+        {{{dataType}}} m_{{paramName}}; //HeaderParams{{/headerParams}}{{#pathParams}}
+        {{{dataType}}} m_{{paramName}}; //PathParams{{/pathParams}}{{#cookieParams}}
+        {{{dataType}}} m_{{paramName}}; //Cookies{{/cookieParams}}
     };
-
 {{/hasAnyRequestSchema}}
 {{/vendorExtensions}}
 {{/operation}}
@@ -49,14 +52,13 @@ public:
     // ===== Response types =====
     // ==========================
 {{/-first}}
+
     /**
     * @brief Response type for {{handlerFunctionName}}.
     */
-    using {{responseType}} = std::variant<
-                                 {{#successType}}{{successType}}{{/successType}}{{^errorTypes}}>;{{/errorTypes}}
-{{#errorTypes}}                               , {{{.}}}{{#-last}}>;{{/-last}}
-{{/errorTypes}}
-
+    using {{responseType}} = std::variant<{{#successCodeToTypes}}{{#successType}}
+                                        {{successType}}{{/successType}}{{#errorCodeToTypes}}{{#-first}} ,{{/-first}}{{/errorCodeToTypes}}{{/successCodeToTypes}}{{^errorCodeToTypes}}>;{{/errorCodeToTypes}}{{#errorCodeToTypes}}
+                                        {{#errorType}}{{errorType}}{{/errorType}}{{^-last}} ,{{/-last}}{{#-last}} >;{{/-last}}{{/errorCodeToTypes}}
 {{/hasAnyResponseSchema}}
 {{/vendorExtensions}}
 {{/operation}}