a pointer to anything, no matter what type it is, is ALWAYS the same size as a variable or embeded in a struct, (8 bytes in 64 arch and 4 bytes in 32 bit) cause it only needs to keep the address in memory to the thing its pointing to.. thats where the 4GB of memory limit for 32 bit architecture came from..cause you could not point to any memory address that would not fit into a 4 byte int

i think what you are saying is the thing the pointer is pointing to, dont have a known size if its a pointer of void.. since its the only untyped type of pointer.. and the programmer would need to check the size of the thing being pointed in memory at runtime.. (so sizeof wouldnt do it)

Also, if you incremment/decrement a pointer , no matter what type it is, you will have a "cursor to the memory" and can even overflow and see memory beyond what you have allocated.. thats where the nasty bugs come from :)

the type in the pointer will only tell (when you increment) by how much this incrementation will go for each iteration..

So if its a integer pointer you will advance 4 by 4 (in 32 bit) and if its a void* 8 by 8.. .. a small int 2 by 2.. a char .. 1 by 1.. etc..