feat: 新增 C++17 Header-only 原生实现 (Closes #1)

README.md

@@ -3,6 +3,7 @@
 > Modern C++ LLM API client with openai-compatible support
 
 [![C++23](https://img.shields.io/badge/C%2B%2B-23-blue.svg)](https://en.cppreference.com/w/cpp/23)
+[![C++17](https://img.shields.io/badge/C%2B%2B-17-blue.svg)](https://en.cppreference.com/w/cpp/17)
 [![C API](https://img.shields.io/badge/C_API-ok-green.svg)](https://en.cppreference.com/w/cpp/23)
 [![Module](https://img.shields.io/badge/module-ok-green.svg)](https://en.cppreference.com/w/cpp/language/modules)
 [![License](https://img.shields.io/badge/license-Apache_2.0-blue.svg)](LICENSE)
@@ -22,6 +23,7 @@ Clean, type-safe LLM API client using C++23 modules. Fluent interface with zero-
 - **Fluent Interface** - Chainable methods
 - **C API** - Full C language support with OOP style
 - **Provider Agnostic** - OpenAI, Poe, and compatible endpoints
+- **C++17 Header-only** - Native support via `#include <llmapi.hpp>` (API identical to C++23)
 
 ## Quick Start
 

README.zh.hant.md

@@ -3,6 +3,7 @@
 > Modern C++ LLM API client with openai-compatible support
 
 [![C++23](https://img.shields.io/badge/C%2B%2B-23-blue.svg)](https://en.cppreference.com/w/cpp/23)
+[![C++17](https://img.shields.io/badge/C%2B%2B-17-blue.svg)](https://en.cppreference.com/w/cpp/17)
 [![C API](https://img.shields.io/badge/C_API-ok-green.svg)](https://en.cppreference.com/w/cpp/23)
 [![Module](https://img.shields.io/badge/module-ok-green.svg)](https://en.cppreference.com/w/cpp/language/modules)
 [![License](https://img.shields.io/badge/license-Apache_2.0-blue.svg)](LICENSE)
@@ -22,6 +23,7 @@
 - **流式介面** - 可鏈式呼叫的方法
 - **C 語言 API** - 完整的 C 語言支援，物件導向風格
 - **提供商無關** - OpenAI、Poe 及相容端點
+- **C++17 純標頭檔** - 原生支援 C++17，僅需 `#include <llmapi.hpp>`（API 與 C++23 一致）
 
 ## 快速開始
 

README.zh.md

@@ -3,6 +3,7 @@
 > Modern C++ LLM API client with openai-compatible support
 
 [![C++23](https://img.shields.io/badge/C%2B%2B-23-blue.svg)](https://en.cppreference.com/w/cpp/23)
+[![C++17](https://img.shields.io/badge/C%2B%2B-17-blue.svg)](https://en.cppreference.com/w/cpp/17)
 [![C API](https://img.shields.io/badge/C_API-ok-green.svg)](https://en.cppreference.com/w/cpp/23)
 [![Module](https://img.shields.io/badge/module-ok-green.svg)](https://en.cppreference.com/w/cpp/language/modules)
 [![License](https://img.shields.io/badge/license-Apache_2.0-blue.svg)](LICENSE)
@@ -22,6 +23,7 @@
 - **流式接口** - 可链式调用的方法
 - **C 语言 API** - 完整的 C 语言支持，面向对象风格
 - **提供商无关** - OpenAI、Poe 及兼容端点
+- **C++17 纯头文件** - 原生支持 C++17，仅需 `#include <llmapi.hpp>`（API 与 C++23 一致）
 
 ## 快速开始
 

examples/cxx17/basic.cpp

@@ -0,0 +1,69 @@
+// Basic usage example - demonstrates both streaming and non-streaming modes
+#include "llmapi.hpp"
+#include <iostream>
+#include <cstdlib>
+
+using namespace mcpplibs;
+
+int main() {
+    auto api_key = std::getenv("OPENAI_API_KEY");
+    if (!api_key) {
+        std::cout << "Error: OPENAI_API_KEY not set" << std::endl;
+        return 1;
+    }
+
+    llmapi::Client client(api_key, llmapi::URL::Poe);
+    client.model("gpt-5").system("You are a helpful assistant.");
+
+    std::cout << "=== llmapi Basic Usage Demo ===\n" << std::endl;
+
+    try {
+        // Example 1: Non-streaming request
+        std::cout << "[Example 1] Non-streaming mode:" << std::endl;
+        std::cout << "Question: What is the capital of China?\n" << std::endl;
+
+        client.user("What is the capital of China?");
+        client.request();
+
+        std::cout << "Answer: " << client.getAnswer() << "\n" << std::endl;
+
+        // Example 2: Streaming request
+        std::cout << "[Example 2] Streaming mode:" << std::endl;
+        std::cout << "Question: Convince me to use modern C++ (100 words)\n" << std::endl;
+
+        client.user("Convince me to use modern C++ (100 words)");
+        std::cout << "Answer: ";
+
+        client.request([](std::string_view chunk) {
+            std::cout << chunk;
+            std::cout.flush();
+        });
+
+        std::cout << "\n" << std::endl;
+
+        // Verify auto-save: get the last answer
+        auto last_answer = client.getAnswer();
+        std::cout << "[Verification] Last answer length: " << last_answer.size() << " chars\n" << std::endl;
+
+        // Example 3: Translate the story to Chinese
+        std::cout << "[Example 3] Translation (streaming):" << std::endl;
+        std::cout << "Question: 请把上个回答翻译成中文。\n" << std::endl;
+
+        client.user("请把上面的故事翻译成中文。");
+        std::cout << "Answer: ";
+
+        client.request([](std::string_view chunk) {
+            std::cout << chunk;
+            std::cout.flush();
+        });
+
+        std::cout << "\n" << std::endl;
+
+    } catch (const std::exception& e) {
+        std::cout << "\nError: " << e.what() << std::endl;
+        return 1;
+    }
+
+    std::cout << "=== Demo Complete ===" << std::endl;
+    return 0;
+}

examples/cxx17/chat.cpp

@@ -0,0 +1,49 @@
+// Simple and elegant AI chat CLI tool using streaming
+#include "llmapi.hpp"
+#include <iostream>
+#include <cstdlib>
+
+using namespace mcpplibs;
+
+int main() {
+    auto api_key = std::getenv("OPENAI_API_KEY");
+    if (!api_key) {
+        std::cout << "Error: OPENAI_API_KEY not set" << std::endl;
+        return 1;
+    }
+
+    llmapi::Client client(api_key, llmapi::URL::Poe);
+    client.model("gpt-5").system("You are a helpful assistant.");
+
+    std::cout << "AI Chat CLI - Type 'quit' to exit\n" << std::endl;
+
+    while (true) {
+        std::cout << "You: ";
+        std::string input;
+        std::getline(std::cin, input);
+
+        if (input == "quit" || input == "q") {
+            std::cout << "\nBye!" << std::endl;
+            break;
+        }
+
+        if (input.empty()) continue;
+
+        try {
+            client.user(input);
+            std::cout << "\nAI: ";
+
+            client.request([](std::string_view chunk) {
+                std::cout << chunk;
+                std::cout.flush();
+            });
+
+            std::cout << "\n" << std::endl;
+
+        } catch (const std::exception& e) {
+            std::cout << "\nError: " << e.what() << std::endl;
+        }
+    }
+
+    return 0;
+}

examples/cxx17/hello_mcpp.cpp

@@ -0,0 +1,20 @@
+// Minimal example - simplest way to use llmapi
+#include "llmapi.hpp"
+#include <iostream>
+#include <cstdlib>
+
+int main() {
+    using namespace mcpplibs;
+
+    llmapi::Client client(std::getenv("OPENAI_API_KEY"), llmapi::URL::Poe);
+
+    client.model("gpt-5")
+          .system("You are a helpful assistant.")
+          .user("In one sentence, introduce modern C++. 并给出中文翻译")
+          .request([](std::string_view chunk) {
+                std::cout << chunk;
+                std::cout.flush();
+          });
+
+    return 0;
+}

examples/cxx17/xmake.lua

@@ -0,0 +1,17 @@
+target("cxx17_hello_mcpp")
+    set_kind("binary")
+    add_files("hello_mcpp.cpp")
+    set_languages("c++17")
+    add_deps("llmapi_cxx17")
+
+target("cxx17_basic")
+    set_kind("binary")
+    add_files("basic.cpp")
+    set_languages("c++17")
+    add_deps("llmapi_cxx17")
+
+target("cxx17_chat")
+    set_kind("binary")
+    add_files("chat.cpp")
+    set_languages("c++17")
+    add_deps("llmapi_cxx17")

examples/xmake.lua

@@ -14,3 +14,4 @@ target("chat")
     add_deps("llmapi")
 
 includes("c")
+includes("cxx17")

include/llmapi.hpp

@@ -0,0 +1,12 @@
+#pragma once
+
+#include <json.hpp>
+#include "llmapi/url.hpp"
+#include "llmapi/openai.hpp"
+
+namespace mcpplibs::llmapi {
+    using OpenAI = openai::OpenAI;
+    using Client = openai::OpenAI;
+    using URL = llmapi::URL;
+    using Json = nlohmann::json;
+} // namespace mcpplibs::llmapi