I think it's more helpful to think of C++ std::optional like Maybe in a functional language rather than as like a nullable type. Its primary use case is as a re

I think it's more helpful to think of C++ std::optional like Maybe in a functional language rather than as like a nullable type. Its primary use case is as a return value from functions, not as a data member. There are many functions where this can make good sense: parsing a string as a number, searching for an element in a collection, trying to load something from a file, taking a square root, etc.