P0332: Strengthen motivation

[mhoemmen]

TensorFlow C++ API link: https://www.tensorflow.org/api_guides/cc/guide

How do they make tensors? Would our notation help?

@hcedwar @dhollman @dsunder

[hcedwar]

Potential relationship with Eigen: http://eigen.tuxfamily.org/dox/group__QuickRefPage.html

[mhoemmen]

Eigen IRC channel: http://eigen.tuxfamily.org/index.php?title=Main_Page#IRC_Channel

Which document should we share with them? '09 document or P0332? All of them?

[mhoemmen]

From what I can tell of TensorFlow, the Tensor type itself has all run-time dimensions:

https://www.tensorflow.org/api_docs/cc/class/tensorflow/tensor

It seems like the point is to create big expression trees and reuse them, less so to make (say) 2x2 matrix-matrix multiplication as fast as possible. Something like TensorFlow might want to use something like mdspan inside, if using run-time compilation. (That would make sense for TF's Const.)