Method lower_bound

cpp/icm/shape_array.hpp:41–59

private:
    auto lower_bound(T index) const noexcept
    {
        T count = span_.size() / stride_;
        T step = count / 2;
        T first = 0;
        T it = 0;
        while (count > 0) {
            it = first;
            step = count / 2;
            it += step;
            if (span_[(it + 1) * stride_ - 1] < index) {
                first = ++it;
                count -= step + 1;
            } else {
                count = step;
            }
        }
        return first;
    }

private:
    base::memory_buffer buffer_;