import std.stdio;

​

void main()

{

    import std.parallelism;

    auto   a   = new A();

    auto   fn  = &a.download;

    string url = "https://raw.githubusercontent.com/dlang/dmd/master/VERSION";

​

    auto async_task = task!fn( url );  // error

​

    async_task.executeInNewThread();

​

    writeln("OK");

}

​

​

class A

{

    void download( string url )

    {

        // DO

    }

}

​