This can be a useful pattern - though I’ve never seen it used for this usecase. A similar one is templating languages (like Jinja) where you need to wrap string

This can be a useful pattern - though I’ve never seen it used for this usecase. A similar one is templating languages (like Jinja) where you need to wrap strings if you want to send HTML to your templates with them being escaped on render. We use something similar where we have a BadNumber class in our code (python). Any operation with another number will also create a BadNumber. It allows us to make sure that these tainted numbers are always obvious.