Rapidjson 是一个 C++ 的快速 JSON 解析器和生成器，使用 SAX/DOM 风格的 API 设计。

示例代码：

// rapidjson/example/simpledom/simpledom.cpp`  #include "rapidjson/document.h"  #include "rapidjson/writer.h"  #include "rapidjson/stringbuffer.h"  #include <iostream>     using namespace rapidjson;     int main() {      // 1. Parse a JSON string into DOM.      const char* json = "{\"project\":\"rapidjson\",\"stars\":10}";      Document d;      d.Parse(json);         // 2. Modify it by DOM.      Value& s = d["stars"];      s.SetInt(s.GetInt() + 1);         // 3. Stringify the DOM      StringBuffer buffer;      Writer<StringBuffer> writer(buffer);      d.Accept(writer);         // Output {"project":"rapidjson","stars":11}      std::cout << buffer.GetString() << std::endl;      return 0;  }

主要特点：

• 体积小，功能全，提供 SAX 和 DOM 风格的 API，仅是 SAX 解析器只有百行代码

• 快速

• 无需依赖其他第三方库

• Compact. Each JSON value is 16 or 20 bytes for 32 or 64-bit machines respectively (excluding text string storage). With the custom memory allocator, parser allocates memory compactly during parsing.

• 完全兼容 RFC4627 ，支持 UTF-8, UTF-16 和 UTF-32.

• Support both in-situ parsing (directly decode strings into the source JSON text) and non-destructive parsing (decode strings into new buffers).

• Parse number to int/unsigned/int64_t/uint64_t/double depending on input

• 支持自定义内存分配。Also, the default memory pool allocator can also be supplied with a user buffer (such as a buffer allocated on user's heap or programme stack) to minimize allocation.

项目主页：http://www.open-open.com/lib/view/home/1428311591963