import std.stdio;

import std.meta;

​

string failedAttempt(string className, Args...)(Args args)

{

    return "foo!(" ~ className ~ ")(args);";

}

​

void foo(T, Args...)(Args args)

{

    writefln("Called with type %s and args %s", T.stringof, args.length);

}

​

interface ICalendarFactory {}

​

enum expand(string className) = "{I" ~ className ~ "Factory a = null; return a;}";

​

template theType(string className)

{

    static if (is(typeof(mixin(expand!className)()) T)) {

        alias theType = T;

    } else {

        static assert(0, "I" ~ className ~ "Factory does not exist");

    }

}

​

void main()

{

    //mixin(failedAttempt!("Calendar")(1));

    alias T = typeof(mixin(expand!"Calendar")());

    writefln("Result of expand call is %s", T.stringof);

    foo!(theType!"Calendar")(1, 2, 3);

    // foo!(theType!"Calendarr")(1, 2, 3);    this will fail with a nice compile time error, as defined on line 23

}