# Pastebin bcvmmzT1
Opinions on assertions vary, because they can be a statement of 
confidence about the correctness of the code. If you're certain that the 
code is correct, then assertions are pointless, since they will never 
fail and you can safely remove them. If you're certain the checks can 
fail (e.g. when testing input data provided by the user), then you dare 
not use assert since it may be compiled away and then your checks will be 
skipped.

It's the situations in between those two that are interesting, times when 
you're certain the code is correct but not *quite* absolutely certain. 
Perhaps you've missed some odd corner case (we're all only human). In 
this case an extra runtime check helps reassure you that any errors will 
be caught as early as possible rather than in distant parts of the code.