On Wed, 20 Jun 2007, Daniel Eischen wrote: DE>On Wed, 20 Jun 2007, Stefan Farfeleder wrote: DE> DE>> On Tue, Jun 19, 2007 at 06:36:39PM -0400, Daniel Eischen wrote: DE>> DE>> > POSIX states that: DE>> > DE>> > o The <sys/socket.h> header shall define the type socklen_t, DE>> > which is an integer type of width of at least 32 bits; see DE>> > APPLICATION USAGE. DE>> > DE>> > and goes on to state: DE>> > DE>> > o The <sys/socket.h> header shall define the unsigned integer DE>> > type sa_family_t. DE>> > DE>> > This seems to imply that our socklen_t should not be an unsigned DE>> > integer (uint32_t), but a signed integer. In APPLICATION USAGE, DE>> > POSIX states: DE>> DE>> I don't understand how you come to that conclusion. Why does not DE>> mentioning whether socklen_t is signed or unsigned imply it should be DE>> signed? DE> DE>Because it explicitly says unsigned for sa_family_t and does not DE>say unsigned for socklen_t. To me, "integer" means a C (signed) DE>integer. The fact that older APIs and implementations used "int" DE>might support the argument to use int32_t just for compatibility DE>reasons. As it stands now, portable code has to have some sort DE>of autoconfig to determine whether or not to use socklen_t or int. DE>I don't see how you can do this with #ifdefs unless you know DE>OS version numbers and when socklen_t first got introduced. In standardese stating 'integer type' means any integer type. It does not imply signed or unsignedness. You might look at paragraph 14 of 6.2.5 of the C standard: "The type char, the signed and unsigned integer types, and the enumerated types are collectively called integer types." DE> DE>> > To forestall portability problems, it is recommended that DE>> > applications not use values larger than 23^1 -1 for the DE>> > socklen_t type. DE>> DE>> That just means that those values will wrap to negative values if DE>> socklen_t is a signed integer type. It ensures that the code works whether the type is signed or unsigned. hartiReceived on Wed Jun 20 2007 - 10:59:10 UTC
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