Boost multi_array库

Question

I need to convert some vba code to c++, the problem is that the algorithm is very particular, it uses matrices up to 15 dimensions, for this reason I decided to use boost multi_array. Now my problem is that in VBA you can change the dimensions at runtime and I am wondering if I can do it in boost multi_array as well.

cheers

Answer 1

You can change the extent (size) of each dimension at runtime, but not the number of dimensions of a variable:

typedef boost::multi_array<double, 3> array_type;

// Create a 2x4x5 array
array_type array3(boost::extents[2][4][5]);

// Reshape (no copy) - The total number of elements must remain the same
boost::array<array_type::index, 3> new_dims{{5, 4, 2}};
array3.reshape(new_dims);

// Resize, keeping currently stored elements by copying them
array3.resize(boost::extents[8][10][5]);

// Create a new array
array3 = array_type(boost::extents[7][6][8]);

Since the number of dimensions is a template parameter of boost::multi_array , you cannot change it at runtime.