site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:sender :to:subject:mime-version:content-type:content-transfer-encoding :content-disposition:x-google-sender-auth; bh=BwOFEN3mskDxg9NEKUPRhJutJfXqsxqCv30f/0y1bA8=; b=bvZXbRur7NZ2iE/bJF+nA/6zf+D7Vey4blaD8Eye2LflqBHlf+sCYW/+ol1EfIIFBX m/4kGPwxgV1tb0hKUokDPeqQtotIcNwpBUu2x563fINcPH5/4z8zmZGhrxdEgDAVScUj qCHiZuVCj8fORXOGiZ3hVHnzahpUMLnht9NVE= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:sender:to:subject:mime-version:content-type :content-transfer-encoding:content-disposition:x-google-sender-auth; b=G1UGGWprJWIoq1PuYskFlYo0/QRduTQtdzgz/jSuBnFTVXzOD6yqx2iLZYWjDvFDQE PciQ4TZ1rJNcLja49Fy11RPm7Ycds7SChSo37WM0TiFUSjQF0lsDdJk2bSKQFgV4RaoC C8ggGl/7ueHV7xnyi/U/FKktGFzK7bxf7IXkE= Hey everyone, This is the most appropriate list I could find for this question pertaining to building weakly-linked libraries and frameworks. Here's a quote from http://developer.apple.com/documentation/MacOSX/Conceptual/BPFrameworks/Conc... "Note: When checking for the existence of a symbol, you must explicitly compare it to NULL or nil in your code. You cannot use the negation operator ( ! ) to negate the address of the symbol." I was simply wondering why this is - what's different between this: if ( !mySymbol ) and this: if ( mySymbol == NULL ) to check whether the symbol exists or not? My understanding of C seems to suggest that comparing something with NULL would be precisely the same thing as comparing it with 0 (overlooking the (void *) cast). Thanks for any insight! David _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.appl... This email sent to site_archiver@lists.apple.com