Multi-dimensional vector initialization

Question

I have following std::vector declaration:

std::vector > > m_input;

I am initializing

Answer 1

my_class::my_class()
 : m_input(100, std::vector< std::vector >(100, std::vector(100) ))
{
}

That said, implementing a multi-dimensional field should be done by projecting into a one-dimensional one, as Viktor said in his comment to the question.