bool_getname P99_CONSTANT P99_DECLARE_ENUM P99_DECLARE_ENUM_GETNAME P99_DECLARE_ENUM_PARSE P99_DECLARE_STRUCT P99_DECLARE_UNION P99_DEFINE_ENUM P99_DEFINE_STRUCT P99_DEFINE_UNION P99_DERIVED_TYPES P99_ENC P99_ENC_DECLARE P99_ENC_INIT P99_ENCP P99_EXT_ARITHMETIC_TYPES P99_EXT_INTEGER_TYPES P99_EXT_REAL_TYPES P99_LITERAL P99_PLAIN_TYPE P99_POINTER_TYPE P99_STD_ARITHMETIC_EXTS P99_STD_ARITHMETIC_TYPES P99_STD_BASIC_EXTS P99_STD_BASIC_TYPES P99_STD_CHARACTER_EXTS P99_STD_CHARACTER_TYPES P99_STD_COMPLEX_EXTS P99_STD_COMPLEX_TYPES P99_STD_FLOATING_EXTS P99_STD_FLOATING_TYPES P99_STD_INTEGER_EXTS P99_STD_INTEGER_TYPES P99_STD_REAL_EXTS P99_STD_REAL_FLOATING_EXTS P99_STD_REAL_FLOATING_TYPES P99_STD_REAL_TYPES P99_STD_SIGNED_EXTS P99_STD_SIGNED_TYPES P99_STD_UNSIGNED_EXTS P99_STD_UNSIGNED_TYPES P99_STRUCT_LITERAL P99_STRUCT_TYPE0 P99_STRUCT_TYPES P99_STRUCT_UNUSE P99_STRUCT_USE P99_UNUSED

P99_DEFINE_UNION #define P99_DEFINE_UNION (   NAME,   ...  ) Value: \ union NAME { \ uint8_t p00_allbytes[sizeof(union { __VA_ARGS__ })]; \ __VA_ARGS__ \ } definition of a union NAME The member declaration(s) should be given as the variable argument list. The difference between this and a straightforward union declaration is that here we introduce a hidden first member that consists of a byte array with just the appropriate length to cover the whole union. The only purpose of this hidden member is to ensure that the default initializer { 0 } initializes the whole union. Otherwise in C99 padding bytes could be omitted from such an initialization, which can lead to surprising results. C1x explicitly states that padding bytes must be initialized to 0. So from then on we can use a straight union definition. Warning Don't assume anything about the ordering of the members of this union. Use designated initializers such as { .toto = { .a = 1, }, }, instead. Remarks argument 0 must be an identifier Definition at line 106 of file p99_type.h.