Hi, Regarding the size of possible bitfields I would like to know why: #include <stdbool.h> struct s { bool f : 2; }; fails to compile in gcc 4.3 and gcc 4.4 but not in gcc 4.2. sizeof(bool) is 1, and C99 6.7.2.1 paragraph 3 seems to imply that the bitfield size shouldn't be bigger than the width of the object. "The expression that specifies the width of a bit-field shall be an integer constant expression with a nonnegative value that does not exceed the width of an object of the type that would be specified were the colon and expression omitted." Therefore I would expect to have 1 to 8 as possible values for an 8 bit/byte architecture. Cheers, -- Paulo Jorge Matos - pocmatos at gmail.com http://www.pmatos.net