The ampersand is ambiguous and can be interpreted by perl as bitwise AND in certain contexts. Since it is not necessary, it is better to always omit the &.
Sounds profound, and it got you quite some XP. It should have been negative XP, because your conclusion is 100% wrong. If you you are afraid to get be bitten by the ambiguity you mention, you should avoid using bitwise and, not the sub-sigil. Because whenever perl has the option to parse an ampersand as a sub-sigil or as a bitwise and, it will parse it as the sub-sigil. 
    $ perl -MO=Deparse,-p -e 'sub foo {} sub bar {} bar & foo()'
    sub foo {
    
    }
    sub bar {
    
    }
    bar(&foo());
    -e syntax OK

[download]
Someone using sub-sigils in the above case would have gotten the binary and parsing: 
    perl -MO=Deparse,-p -e 'sub foo {} sub bar {} &bar & &foo()'
    sub foo {
    
    }
    sub bar {
    
    }
    (&bar & &foo());

[download]
So, you have two options to avoid this ambiguity: either avoid using binary and, or to always use the sub-sigil.
Perl --((8:>*

In reply to Re^2: What's so bad about &function(...)? by Perl Mouse
in thread What's so bad about &function(...)? by japhy

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