Water troughs as raised beds?

Recently, I saw a picture of someone in this zone using the metal troughs sold for livestock watering (and that I used in Florida for water features) being used for raised vegetable beds. Anyone tried this? I would remove the plug and line the bottom with rock, but do you also drill additional drainage holes? Thought this an alternative for the traditional raised beds and something that could be used in the landscaping.

I have seen that done for flower beds , pictures of growing potatoes that way . I would guess a couple of drainage holes placed in the bottom would be part of that .
Last time i saw that a string trelles hanging over the front , with the trough the trellis all hidden by morning glories or hanging petunia plants . It looked pretty good as far as I could see (quick pass by)

I did see a program on tv a few years ago where troughs were used for veggies, in particular tomatoes because of the depth for root development. I don't think you need to use any rock in the bottoms as long as you add some drainage holes. You could make the holes the same size as available plugs if you want to use the troughs for something else in future and that would keep your options open instead of committing the trough to only growing plants.

Thanks to you both and for any future responses STU