Vibe/Mysql Testing

[Vino]

Hi All,

   Request your help on the below code and error

Error:
source\app.d(25,15): Error: none of the overloads of writeBody 
are callable using argument types (VariantN!20LU), candidates are

Code:
import vibe.vibe;
import std.array : array;
import mysql;
import std.stdio;
import std.range;

void main()
{
	auto settings = new HTTPServerSettings;
	settings.port = 8080;
	settings.bindAddresses = ["127.0.0.1"];
	listenHTTP(settings, &hello);

	logInfo("Please open http://127.0.0.1:8080/ in your browser.");
	runApplication();
}

void hello(HTTPServerRequest req, HTTPServerResponse res)
{
	auto connectionStr = 
"host=test.srv.com;port=3910;user=testusr;pwd=xxxx#;db=test";
	Connection conn = new Connection(connectionStr);
	scope(exit) conn.close();
	ResultRange range = conn.query("SELECT host_name FROM 
`hosts_coll`");
	Row row = range.front;
	res.writeBody(row[0]);
}

From,
Vino.B