一個 C++ 的快速 JSON 解析器和生成器：Rapidjson

Rapidjson 是一個 C++ 的快速 JSON 解析器和生成器，使用 SAX/DOM 風格的 API 設計。

示例代碼：

// 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;
}

主要特點：

• 體積小，功能全，提供 SAX 和 DOM 風格的 API，僅是 SAX 解析器只有百行代碼

• 快速

• 無需依賴其他第三方庫

• 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

• 支持自定義內存分配。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.

項目主頁：http://www.baiduhome.net/lib/view/home/1428311591963