Apple patents a way to wirelessly transfer power between devices

Today, a patent was published at the USPTO from Apple that describes an interesting way to charge Apple devices. The patent describes a wireless charging coil that could transmit current bi-directionally. Thus, a theoretical iPad or MacBook with the same wireless could transfer a charge to an iPhone X or iPhone 8 with a depleted battery. We know that there is currently no such thing as an iPad or MacBook with induction coils for the purpose of wireless charging. However, should Apple put the idea into fruition, it could be an interesting last-alternative to charge a dead iPhone...