How should one test for seteuid()'s existence?

[Paul Eggert]

Submitted-by: eggert at twinsun.uucp (Paul Eggert)

I've heard that IEEE will publish a separate supplement to IEEE Std 1003.1
(ISO/IEC 9945-1) that covers seteuid(), among other issues.  In the latest
draft of this supplement, how should a program test for the existence of
seteuid()?  Will the following test work?

	#include <unistd.h>

	#if _POSIX_VERSION > 199009L
		... seteuid() exists ...
	#endif

Volume-Number: Volume 22, Number 119