Question

I have a situation where a class holds a vector of constant size 5. I need the data from the vector as an array of size 5 as our std::vector implementation doesn’t appear to use contiguous memory (please don’t argue about that, I know it should and we’ve checked it to death). The contiguous memory block is required so we can uuencode/uudecode the memory block easily (those turn an arbitrary memory block into a string).

I’m finding it difficult to return a statically sized array. I can do it by reference or I can do it by wrapping a statically sized array in a structure – but both are a little agitating. By reference requires the calling code to declare the array first and pass it in to the code, and the other option requires that I make an extra structure just for this purpose.

class A {
    public:
        /*return type*/ GetVectorAsArray(/*params*/) { /* implementation */ }

    private:
        std::vector<X> m_vec;
};

So, assuming I need to call GetVectorAsArray, what’s the cleanest way to return the 5 values in m_vec to the calling code? You can put whatever you want in return type or params and implementation.

Answer 1

boost::array is intended for arrays of fixed size, you can always use that. It uses contiguous memory.

Later edit: as correctly pointed out by commenters, std::array is available in the new standard.