File Ex from std_stdio won't compile

[Paul]

I copied the code below from this site under the std.stdio 
library reference section and tried to compile it.  I downloaded 
D2/Phobos.  Compiler says "fileread.d(4): Error: undefined 
identifier File"

If I add import std.stdio to the beginning it get ; expected, 
function declaration w/o return type, etc.

Assistance is greatly appreciated.

 void main(string args[])
{
    auto f = File("test.txt", "w"); // open for writing
    f.write("Hello");
    if (args.length > 1)
    {
        auto g = f; // now g and f write to the same file
                    // internal reference count is 2
        g.write(", ", args[1]);
        // g exits scope, reference count decreases to 1
    }
    f.writeln("!");
    // f exits scope, reference count falls to zero,
    // underlying FILE* is closed.
}