C++ armadillo庫 cube 轉 mat

#include <armadillo>

cube A = randu<cube>(5,4,3);

方法一
A.reshape(5*4, 3, 1);
mat B = A.slice(0);

方法二
mat C = reshape( mat(A.memptr(), A.n_elem, 1, false), 5*4, 3);