Simple Hello World using Crow

crw_server.cpp

#include "crow_all.h"

int main()
{
    crow::SimpleApp app;

    CROW_ROUTE(app, "/helloworld")
    ([]{
      crow::json::wvalue x;
      x["message"] = "Hello, World!";
      return x;
    });

    app.port(3000).multithreaded().run();
}