What is the most efficient way to initialize a 3D vector?

Question

I have a 3D string vector in C++:

vector>> some_vector

That I am trying is to find a fast method to all

Answer 1

I think I'd optimize it by allocating one large block of memory instead of a lot of little ones. This one is only 2D instead of 3D, but gives the basic idea:

template 
class matrix { 
    size_t columns_;
    std::vector data;
public:
    matrix(size_t columns, size_t rows) : columns_(columns), data(columns*rows) {}

    T &operator()(size_t column, size_t row) { return data[row*columns_+column]; }
};

For 3D, you'll need to deal with "planes" (or something) along with rows and columns, but the basic idea is pretty much the same.