[moe]

Your link describes (and encourages) exactly the laborious emulation of Checked Exceptions that I was talking about in my above comment.

It doesn't make the guard clauses disappear. It merely forces the programmer to manually aggregate them at a higher level with even more boilerplate code.

[mahyarm]

If my guard clause is doing the same thing for 20 lines, it increases readability. Could be an optimization point too!