That's not really a C++ construct, as much as it is a hold-over from C, kept around to retain compatibility with existing code. If you're writing new C++ code,

That's not really a C++ construct, as much as it is a hold-over from C, kept around to retain compatibility with existing code. If you're writing new C++ code, you're in no way forced to use it. You can use constants or inline functions to achieve the same result in almost all cases.