Description:
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In my opinion it should be possible to pass by reference when using variable-length argument lists. I know that there are quite a lot of workarounds for this but none of them is really appealing to me. For the sake of orthogonality it should be possible to use user defined functions with variable-length argument lists in the same way as without.
See my listing for a possible use of this.
Do not tell me these variables could be packed into an array.
This feature request does not contain scope inheritance as requested in bug #11472.

Reproduce code:
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// We've got some strings from user input
// named $a, $b and $c
// and want them to be escaped and converted somehow

// with passing by reference this could look like
my_conversion($a,$b,$c);

// possible workaround now:
list($a,$b,$c) = my_conversion($a,$b,$c)