Flag proposal

[foobar]

People here already noted most advantages and disadvantages of this proposal so I'll just add one more: KISS.
I too am against this proposal since it's very unKISS. 
I think, that either you really need a separate enum type to document the different values and hence use *should* define the enum or you don't really need it and hence KISS it with a plain boolean. 
I see zero benefit from adding so much complexity here. Are we trying to kill a fly with a hammer (and by that i mean the vehicle)?

I see no benefit in adding redundant "Yes" / "No" values.

Regarding named arguments, I don't like this "feature" and believe that it's more trouble than its worth. For example, Ruby managed to live without it and Rails uses AAs instead. 

And finally, Andrei's complain about scrolling up and down because of this so called boilerplate (7 lines of code in all of phobos): 
Even though D has a far superior module system compared to c++ (which has no such system whatsoever) you still chose to implement library-in-a-file. You even went so far as to add "groups" to DDoc. Is there some sort of weird metric at Facebook that gives you a bigger bonus if you manage to cram more code per file? Are you getting deducted per the amount of files you've added?