Your mission

Write swap_bytes, which exchanges the size bytes at a with the size bytes at b, whatever type those bytes hold.

See it in action

int x = 42, y = -7; swap_bytes(&x, &y, sizeof(int))

x=-7 y=42

char s[] = "left|right"; swap_bytes(s, s + 5, 1)

reft|light

int x = 1234; swap_bytes(&x, &x, sizeof(int))

x=1234

Your checklist

• a and b each point to at least size bytes you may read and write. size can be any value, 0 included.
• After the call, the size bytes at a hold what the size bytes at b held, and the other way round. No byte outside those two ranges changes.
• a and b can be the same address. Nothing changes then. They never point into ranges that overlap only in part.
• Tests print the objects after the call, read back with their real type.

Your mission

Write swap_bytes, which exchanges the size bytes at a with the size bytes at b, whatever type those bytes hold.

See it in action

int x = 42, y = -7; swap_bytes(&x, &y, sizeof(int))

x=-7 y=42

char s[] = "left|right"; swap_bytes(s, s + 5, 1)

reft|light

int x = 1234; swap_bytes(&x, &x, sizeof(int))

x=1234

Your checklist

• a and b each point to at least size bytes you may read and write. size can be any value, 0 included.
• After the call, the size bytes at a hold what the size bytes at b held, and the other way round. No byte outside those two ranges changes.
• a and b can be the same address. Nothing changes then. They never point into ranges that overlap only in part.
• Tests print the objects after the call, read back with their real type.