sort_json by name

sort_json.cpp

#include "rapidjson/document.h"
#include "rapidjson/writer.h"
#include "rapidjson/stringbuffer.h"
#include <algorithm>
#include <iostream>

using namespace rapidjson;

int main () {
    Document d;
    d.Parse("{\"c\":3, \"b\":2, \"a\":1, \"d\":4}");
    std::sort(d.MemberBegin(), d.MemberEnd(), [](const Value::Member& lhs, const Value::Member& rhs){
        return std::strcmp(lhs.name.GetString(), rhs.name.GetString()) < 0; });
    StringBuffer sb;
    Writer<StringBuffer> writer(sb);
    d.Accept(writer);
    std::cout << sb.GetString() << std::endl;
}