you could use vector::resize() instead and delete the following for loop and the dummy_coords variable.
if you write ```vec_nodes.resize(fem_dim.n_nodes);``` the standard constructor is used for the new elements. it *should* be possible to write ```vec_nodes.resize(fem_dim.n_nodes, MeshLib::Node(0,0,0));``` or whatever default value you want to insert, I haven't tested that though.