C++ Suppress Automatic Initialization and Destruction

Question

How does one suppress the automatic initialization and destruction of a type? While it is wonderful that T buffer[100] automatically initializes all the elemen

Answer 1

You can create the array as array of chars and then use placement new to create the elements when needed.

template 
class Array
{
private:
    char m_buffer[KCount*sizeof(T)]; // TODO make sure it's aligned correctly

    T operator[](int i) {
        return reinterpret_cast(m_buffer[i*sizeof(T)]);
    }

---

After re-reading your question it seems that you want a sparse array, this sometimes goes by the name of map ;o) (of course the performance characteristics are different...)

template 
class SparseArray {
    std::map m_map;
public:
    T& operator[](size_t i) {
        if (i > KCount)
            throw "out of bounds";
        return m_map[i];
    }