Nope, C doesn't allow such assignment even then. You're thinking of casts. For casts, the C standard requires that a pointer to a struct can convert to a pointe

Nope, C doesn't allow such assignment even then. You're thinking of casts. For casts, the C standard requires that a pointer to a struct can convert to a pointer to its initial member and vice versa, this is specified under "Structure and union specifiers". You need to actually spell it out with a cast though, C doesn't allow that to be done as an implicit conversion.