Accessing bit-field in C by its address

Question

What is the reason behind not allowing to access a bit field in C using its address, is it cause it might not be an address that is not system word aligned ..? or as it doesn't make sense to get bit's address within a byte...?(cause this types pointer arithmetic will be awkward ?)

Answer 1

Bits do not have addresses. That's why you can't refer to them by address. The granularity of addressing is the char.

I guess the reasoning is that the language was design to match the architecture it targeted, and I know of no machine which allows addressing of individual bits.

Answer 2

The smallest unit of addressable memory in C is a char, because this corresponds to the smallest unit of addressable memory on most CPU architectures.^* It doesn't make sense to talk about the address of a bit.

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_{* One could imagine a hypothetical machine that allowed addressing of individual bits, but it would be pretty esoteric.}