In v11.3, NetSharedArray[] and NetInsertSharedArray[] give us a mechanism of sharing weights and biases across neural networks, and this is exciting because now we can train siamese networks and do deep image ranking, and other related applications.

I don't see any applications section for either of these symbols in the documentation center, but I'd like to see how one might implement a basic Triplet Network, for example FaceNet. The problem is that I'm not sure how to write the triplet hinge loss in Mathematica.

References:

• https://arxiv.org/pdf/1404.4661.pdf
• https://www.coursera.org/learn/convolutional-neural-networks/lecture/HuUtN/triplet-loss