Code shared from run.dlang.io.

main.d

@safe:
import std.stdio;

class Foo
{
    void bar()
    {
        *cast(int*)(0xdeadbeef) = 5; // Do something unsafe here

        writeln("Foo:bar() - Me too!");
    }
}

void main()
{
    writeln("Main() - I'm safe!");
    (new Foo()).bar();
}