Diagonal minecart tracks

One of my issues with minecart tracks is that you have a terrible time trying to build diagonal tracks since the existing minecart rails only go in the four cardinal directions. I could try to make a diagonal rail by making a bunch of 90 degree turns, but then curved powered rails don't exist in the game. Also, curved minecart rails can't go up and down slopes. So I would love to see diagonal minecart tracks that allow me to build diagonal rail lines, and go up and down slopes without having to route my minecart tracks weirdly.