The ISO/IEC C standard requires the following implementation details to be documented for structured data types:
the outcome when a member of a union is accessed using a member of different type
the padding and alignment of members of structures
whether a plain int bitfield is treated as a signed int bitfield or as an unsigned int bitfield
the order of allocation of bitfields within a unit
whether a bitfield can straddle a storage-unit boundary
the integer type chosen to represent the values of an enumeration type.
See C and C++ Implementation Details for more information.
See Unions for information.
See Enumerations for information.
See Structures for information.
See Bitfields for information.