When exploring the design of nullable pointers in C and comparing them with other languages like C# and TypeScript, which have constructors, I realized that C might benefit from a way to represent transient states, the state equivalent of when object is being constructed.

The C++ mutable keyword came to mind as a potential solution.

During the object creation (or destruction), the instance is considered to be in a transitional state, where the usual constraints—such as non-nullable pointers and immutability—are lifted. Once the transitional phase is over and the object is returned, the contract that governs the object (such as immutability of name and non-nullability of pointers) is fully reinstated.