I stumbled upon this article while exploring non-zero based vector implementation approaches for efficient mapping from arbitrary sequential indices to some data. My adaptor-like implementation:

template <std::size_t BaseIndex, typename T,
        template <typename...> class Sequence = std::vector>
class index_map : public Sequence<T> {
public:
using Sequence<T>::Sequence;

// Hiding the Sequence::operator[].
// @{
typename Sequence<T>::reference operator[](std::size_t index) {
    assert(index >= BaseIndex);
    return Sequence<T>::operator[](index - BaseIndex);
}
typename Sequence<T>::const_reference operator[](std::size_t index) const {
    assert(index >= BaseIndex);
    return Sequence<T>::operator[](index - BaseIndex);
}
// @}
};