Structure in vivo alignment rules

Byte alignment details are related to compiler implementations, but in general, three guidelines are met:

1) The first address of a struct variable can be divisible by the size of its widest base type member;

2) the offsets (offset) of each member of the struct relative to the first address of the struct are an integer multiple of the member size, and if necessary, the compiler adds padding bytes between the members (internal adding);

3) The total size of the struct is an integer multiple of the size of the structure's widest base type member, and if necessary the compiler will add padding bytes (trailing padding) after the last member.

Structure in vivo alignment rules