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# The Weird and The Wonderful

The Weird and The Wonderful forum is a place to post Coding Horrors, Worst Practices, and the occasional flash of brilliance.

We all come across code that simply boggles the mind. Lazy kludges, embarrassing mistakes, horrid workarounds and developers just not quite getting it. And then somedays we come across - or write - the truly sublime.

Post your Best, your worst, and your most interesting. But please - no programming questions . This forum is purely for amusement and discussions on code snippets. All actual programming questions will be removed.

 Reversing a logical ( OR ) albert_redditt2-Sep-21 12:31 albert_redditt 2-Sep-21 12:31
 Re: Reversing a logical ( OR ) PIEBALDconsult2-Sep-21 13:13 PIEBALDconsult 2-Sep-21 13:13
 Re: Reversing a logical ( OR ) Jon McKee2-Sep-21 14:11 Jon McKee 2-Sep-21 14:11
 Re: Reversing a logical ( OR ) Matias Lopez18-Oct-21 12:11 Matias Lopez 18-Oct-21 12:11
 Re: Reversing a logical ( OR ) Rick York2-Sep-21 15:43 Rick York 2-Sep-21 15:43
 Re: Reversing a logical ( OR ) jschell5-Sep-21 10:24 jschell 5-Sep-21 10:24
 Re: Reversing a logical ( OR ) James Curran24-Sep-21 6:53 James Curran 24-Sep-21 6:53
 Re: Reversing a logical ( OR ) harold aptroot5-Oct-21 22:09 harold aptroot 5-Oct-21 22:09
 The formula is correct (though as mentioned it doesn't "undo" the OR, it computes the OR in terms of other operations) and I'll prove it algebraically, starting at the end and deriving that it must be equal to `v1 | or_val`. Copy Code ```( v1 ^ or_val ) + ( v1 & or_val ) = (the left and right operands do not "intersect", their bitwise AND is zero, in that case A + B == A | B) ( v1 ^ or_val ) | ( v1 & or_val ) = (OR distributes over AND) (v1 ^ or_val | v1) & (v1 ^ or_val | or_val) = (A ^ B | B == A | B) (or_val | v1) & (v1 | or_val) = (A AND A == A) v1 | or_val```
 Re: Reversing a logical ( OR ) Phil Hodgkins5-Oct-21 23:28 Phil Hodgkins 5-Oct-21 23:28
 Re: Reversing a logical ( OR ) Rob Grainger14-Oct-21 11:06 Rob Grainger 14-Oct-21 11:06
 Re: Reversing a logical ( OR ) Richard Deeming15-Oct-21 0:17 Richard Deeming 15-Oct-21 0:17
 That's one way to do it Kent Sharkey17-Aug-21 11:21 Kent Sharkey 17-Aug-21 11:21
 Re: That's one way to do it Mike Hankey17-Aug-21 11:38 Mike Hankey 17-Aug-21 11:38
 Re: That's one way to do it PIEBALDconsult17-Aug-21 11:50 PIEBALDconsult 17-Aug-21 11:50
 Re: That's one way to do it Jon McKee17-Aug-21 12:18 Jon McKee 17-Aug-21 12:18
 Re: That's one way to do it den2k885-Oct-21 22:17 den2k88 5-Oct-21 22:17
 Re: That's one way to do it Dan Neely29-Nov-21 4:23 Dan Neely 29-Nov-21 4:23
 Re: That's one way to do it Jon McKee17-Aug-21 12:10 Jon McKee 17-Aug-21 12:10
 Re: That's one way to do it PIEBALDconsult17-Aug-21 12:14 PIEBALDconsult 17-Aug-21 12:14
 Re: That's one way to do it Jon McKee17-Aug-21 12:23 Jon McKee 17-Aug-21 12:23
 Re: That's one way to do it jsc4218-Aug-21 23:38 jsc42 18-Aug-21 23:38
 Re: That's one way to do it Member 798912217-Aug-21 12:31 Member 7989122 17-Aug-21 12:31
 Re: That's one way to do it James Walsh Jr17-Aug-21 14:53 James Walsh Jr 17-Aug-21 14:53
 Re: That's one way to do it Brisingr Aerowing17-Aug-21 15:08 Brisingr Aerowing 17-Aug-21 15:08
 Re: That's one way to do it PIEBALDconsult17-Aug-21 15:43 PIEBALDconsult 17-Aug-21 15:43
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