std.typecons.Flag -- public import for API users?

[rcorre via Digitalmars-d-learn]

If I am developing a library and some of my functinos take a 
std.typecons.Flag as an argument, should I 'public import 
std.typecons: Flag, Yes, No'?

It seems like it would be a pain for users of the library to have 
to import this separately whenever they use my library, but I'm 
not sure what the stance is on having your modules `public 
import` standard-library modules.

In general, is it considered bad form to 'public import' modules 
from phobos?