You will find the following code equivalent to $array[++$x] = ++$x;: 

do { local @_;
     alias $_[0] = ++$x;          # Aliases to $x
     alias $_[1] = $array[++$x];
     $_[1] = $_[0]
   };

[download]

As you can see, the LHS is fully evaluated before the RHS, yes you still get the effect you say can't happen under those conditions.

If you don't have Data::Alias (like me), you can use the following code: 

do { our $arg0; local *arg0 = \( ++$x         );
     our $arg1; local *arg1 = \( $array[++$x] );
     $arg1 = $arg0;
   }

[download]

In reply to Re^5: Will "$_[0]=shift" always resolve shift first? by ikegami
in thread Will "$_[0]=shift" always resolve shift first? by kyle

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