alt Hacker NewsAnd the consequence is that, at least in C++, we don't see the benefit you describe of "objects can never be in an uninitialized or partially-initialized state".
Anyway, I think this could be fixed, if we wanted to. C just describes the objects as being uninitialized and has a bunch of UB around uninitialized objects. Nothing in C says that an implementation can't make every uninitialized object 0. As such, it would not harm C interoperability if C++ just declared that all variable declarations initialize variables to their zero value unless the declaration initializes it to something else.
It's possible to fix this in application code with a Primitive<T> or NoDefault<T> wrapper that acts like a T, except doesn't have a default constructor. Use Primitive<int> wherever you'd use int that it matters (e.g. struct fields), and leaving it uninitialized will be a compiler error.