The most awesome "forward to member" solution?

[Andrei Alexandrescu via Digitalmars-d]

OK, here's what I have now - two templates that are self contained and 
work well:

The first uses opDispatch to dispatch to a member. The second is a 
simple string function that generates the appropriate code. As discussed 
the latter composes but the former doesn't.

mixin template dispatchToMember(alias member, methods...)
{
     import std.algorithm : among;
     import std.traits : ParameterTypeTuple;
     template opDispatch(string sym)
     if ((methods.length == 0 || sym.among(methods)))
     {
         auto ref opDispatch(ParameterTypeTuple!(__traits(getMember, 
member, sym)) args)
         {
             return __traits(getMember, member, sym)(args);
         }
     }
}

string forwardToMember(string member, string[] funs...)
{
     string result = "    import std.traits : hasMember, 
ParameterTypeTuple;\n";
     foreach (fun; funs)
     {
         result ~= "
     static if (hasMember!(typeof("~member~"), `"~fun~"`))
     auto "~fun~"(ParameterTypeTuple!(typeof("~member~"."~fun~")) args)
     {
         return "~member~"."~fun~"(args);
     }\n";
     }
     return result;
}


Andrei