> On Oct 13, 2015, at 3:24 PM, Graham Cox <[email protected]> wrote: > In a piece of code I haven’t worked on in a while, I’m suddenly getting a new > warning which I’ve never seen before: > > “Multiple unsequenced modifications to ‘ix’” > > Code is: > > > ix = ++ix % guess.count; > > where ix is a NSUInteger. > > Is this telling me that the order of the preincrement and the mod operation > is undefined? Surely a preincrement is defined to happen first, that’s why > it’s called a PREincrement? Or does the warning refer to something else? I’ve > used this form of expression for years without any issues, why is it suddenly > one?
Pre-increment is defined to return the value that would be stored in its operand. The actual store to the operand is indeterminately sequenced with returning that value, however. John. _______________________________________________ Cocoa-dev mailing list ([email protected]) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [email protected]
