[Effective C++] Item 18

Many client errors can be prevented by the introduction of new types, such as

struct Day {
    explicit Day(int d)
    :val(d) {}
    
    int val;
}

Once the right types are in place, it can sometimes be reasonable to restrict the values of those types.

reliable initialization of non-local static objects can be problematic

have your types behave consistently with the built-in types

"cross-DLL" problem: when an object is created using new in one DLL but is deleted in a different DLL