@safe, pure and nothrow at the beginning of a module

[Philippe Sigaud via Digitalmars-d-learn]

So I'm trying to use @safe, pure and nothrow.

If I understand correctly Adam Ruppe's Cookbook, by putting

@safe:
pure:
nothrow:

at the beginning of a module, I distribute it on all definitions, 
right? Even methods, inner classes, and so on?

Because I did just that on half a dozen of modules and the 
compiler did not complain. Does that mean my code is clean(?) or 
that what I did has no effect?