The language spec for C constrains the memory layout of a struct. From 6.7.3.2.7 of the draft spec: > a structure is a type consisting of a sequence of members

The language spec for C constrains the memory layout of a struct. From 6.7.3.2.7 of the draft spec: > a structure is a type consisting of a sequence of members, whose storage is allocated in an ordered sequence, (emphasis added) https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3220.pdf https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3220.pdf