But `s` is defined somehow, and it is not defined as a `uint32_t * ` (or else you would not need the cast). It is usually defined as `char * `. The memory being

But `s` is defined somehow, and it is not defined as a `uint32_t * ` (or else you would not need the cast). It is usually defined as `char * `. The memory being read is reachable by dereferencing `s`, a `char * `, and by dereferencing `(uint32_t * )s`, a `uint32_t * `. Thus, type punning and aliasing. Each byte of memory should be reachable only by pointers/array indexes of a single type (and anything that is not a `char * ` can be accessed by `char * `).