How can I add string pairs to a document of rapidjson
<p>I want to create a json string using rapidjson. But I got a error: unable to convert <code>std::string</code> to <code>rapidjson::Type</code>.</p>

<pre><code>int x = 111;
string className = "myclass";

Document doc;
auto&amp; allocator = doc.GetAllocator();

doc.AddMember("x", Value().SetInt(x), allocator);
doc.AddMember("className", className, allocator);

unordered_map&lt;string, string&gt;&amp; map = sprite-&gt;toMap();
for (const auto&amp; pair : map) {
    Value key(pair.first.c_str(), pair.first.size(), allocator);
    doc.AddMember(key, pair.second, allocator);
}

StringBuffer sb;
Writer&lt;StringBuffer&gt; writer(sb);

doc.Accept(writer);
log("json string: %s", sb.GetString());
</code></pre>