box_temp.data<float>() will give you a float* which you can liberally use. You do have to deal with strides yourself. An alternative could be to use box_vec.reserve(...), create a tensor view on that with auto box_vec_view = torch::from_blob 111 (but I don’t know if it should be at::from_blob or torch::) and box_vec_view.copy_(out1) the tensor there.
Note that from_blob does not take ownership of the memory, I use that because it’s impossible to create a std::vector with memory from elsewhere.
Best regards
Thomas
P.S.: The preferred way is to use the C++ category rather than a [Libtorch] prefix.