If only c++ had some sort of static type system which could be leveraged to provide compile-time checks...

But seriously, this is a large part of the power of c++'s type system. Taking the article's example, if the argument types were of (user class) 'non_zero_float', there's no possibility for error.

You still have to check that your input is non-zero at some point, but you've now focused it into one place (the 'non_zero_float' class ctor), and other chunks of your program depending on those type semantics no longer need to worry about it.