You can use error codes or, better, a Result<T, E> template in C++, but throwing an exception is the only sane way to signal an error from a C++ constructor tha

You can use error codes or, better, a Result<T, E> template in C++, but throwing an exception is the only sane way to signal an error from a C++ constructor that I know of. The alternatives are awkward: you either stick an error code on the struct, which the caller can check after construction, or write an error code to the caller through an out parameter. In either case, the class implementation now must be concerned with handling objects in some partly-initialized, "error" state.