Dynamic method example in TDPL

[Joel Christensen]

I've typed this example program in, but it doesn't compile. I looked up 
the The D programming language errata but it wasn't listed. I'm using 
DMD v2.048.

>>
/**
        Date: Aug 20, 2010
        This was copied from TDPL book pages 386 - 387
*/
module dynamicmethods;
import std.stdio;
import std.variant;

alias Variant delegate(Dynamic self, Variant[] args...) DynMethod;

class Dynamic {
        private DynMethod[string] methods;
        void addMethod(string name, DynMethod m) {
                methods[name] = m;
        }
        void removeMethod(string name) {
                methods.remove(name);
        }
        // Dispatch dynamically on method
        Variant call(string methodName, Variant[] args...) {
                return methods[methodName](this, args);
        }
        // Provide syntactic sugar with opDispatch
        Variant opDispatch(string m, Args)(Args args...) {
                Variant[] packedArgs = new Variant[args.length];
                foreach (i, arg; args) {
                        packedArgs[i] = Variant(arg);
                }
                return call(m, args);
        }
}

void main() {
        auto obj = new Dynamic;
        obj.addMethod("sayHello",
                Variant(Dynamic, Variant[]) { //#error here. (found '{' 
expecting ','
                        writeln("Hello, world!");
                        return Variant();
                });
        obj.sayHello(); // Prints "Hello, world!"
}
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