AFAIK STL vector will move objects instead of copying when re-allocating internal storage as long as stored class provides move constructor/assignment.
This can be very efficient both in terms of memory and speed when working with large matrices:

Code: Select all

std::vector<MatrixXd> v;

for (int i= 0; i<100; i++)
{
    MatrixXd big_mat = ...;
    v.push_back(std::move(big_mat));

    MatrixXd another_big_mat = ...;
    v.insert(v.begin(), std::move(another_big_mat));
}

In the above example no copy of matrix should be created? Right?

hm, better use emplace_back instead of push_back(move), emplace_back should fail to compile if the type is not MoveInsertable