I ran the following line of code with strange results.
$prevFlagBin |= $flagBin;

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Before running this line the debugger said: 
x ($prevFlagBin, $flagBin)
0  3221225472
1  3758096384

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After it said this: 
0  '37792;77?6'
1  3758096384

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Also in the debugger I found: 
  DB<4> x 3221225472 | 3758096384
0  3758096384

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Correct answer!

But 
  DB<6> x '3221225472' | '3758096384'
0  '37792;77?6'

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So I figured it was going into character context.

So I tried: 
  DB<8> x 0 | '3221225472' | '3758096384'
0  3758096384

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And that worked.
So I modified my code to: 
$prevFlagBin = 0 | $prevFlagBin | $flagBin;

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Which works.

So my question is, is this a perl bug?
Do I need to understand something about the context here?
Do I get a performance advantage by using '|=' since that would be fast in C?
Have I lost that advantage due to this?

Comments appreciated.

-HarveyK

update (broquaint): changed plain formatting => <code> tags

In reply to Bug in perl bitwise or?? by Anonymous Monk

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