[leoedin]

Instances of types also have different memory addresses - that doesn't mean they're different types.

I think it's a hard problem because every microcontroller is different. A pretty common pattern in C land is to define a peripheral struct (eg I2C, GPIO) which has a 32 bit uint for each register in the peripheral, and then create a pointer to the physical memory address for each peripheral. That means you can write functions which take an I2C peripheral without knowing which one - and so if you decide later to move over to I2C2 it's just a case of changing one variable.

That works because broadly there's very little difference between I2C1 and I2C2, or GPIO0 and GPIO1, in the microcontroller. If they start being very different then you'd have problems with that approach.