I would like to do a compile-time mapping of an array accessor to a list of scalars as in the following class:
class MyArray1 { public: double& operator[](int n) { ??? }
private: double a0, a1, a2, a3 ; } ;
Well, using an union would typically works correctly. And if you are using a compiler with some kind of property, this might be another solution. FInally, you could have functions that access the array. A final solution, would be to derive from a struct and do a reinterpret_cast. --- The first solution might look like : union { struct { double a0, a1, a2, a3 ; } scalar; double array[4]; }; but then you would need to qualify names. --- For the second solution, you will be able to have the desired syntax for the caller... but properties are not standard C++ and are not protable. --- For the third solution, it will be something like : class MyArray1 { public: double &a1() { return array[1]; } double const &a1() const { return array[1]; } private: double array[4]; }; --- The forth solution is something like : struct MyArray1Struct { double a0, a1, a2, a3; }; class MyArray1 : private MyArray1Struct { public: double& operator[](int n) { return reinterpret_cast<double(&)[4]>(static_cast<>(*this)); } double const & operator[](int n) const { return reinterpret_cast<double const(&)[4]>(static_cast<>(*this)); } };