You may as well use the standard if/else and avoid a temporary.
No temporary variable, and no if/else, replacing 
    EXPR1 if $x;
    EXPR2 unless $x;

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can be done as: 
   ((sub {EXPR1}, sub {EXPR2})[!!$x || 0])->();

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except that EXPR1 and EXPR2 in the latter have their own scopes - but you have that with an if/else construct as well.

If EXPR1 and EXPR2 are function calls using the same arguments, as in: 

    foo($arg, @args) if $x;
    bar($arg, @args) unless $x;

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one could write: 
    ((\&foo, \&bar)[!!$x || 0])->($arg, @args)

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In reply to Re^2: Useless unless by Anonymous Monk
in thread Useless unless by GrandFather

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