sharping naturals

[Brother Gabriel-Marie]

When you use key signatures like A major or B Major you end up with a lot of naturals in the score for which you may have to manually add sharps.

Is there a switch that will automatically sharp all the naturals?
I was looking at this:
http://www.lilypond.org/doc/v2.19/Documentation/notation/displaying-pitches#automatic-accidentals

This was the closest I could see:
\accidentalStyle modern