Hi Derrick,

I don't consider to be bug, that it cannot be used as function argument.

However I consider to be bug, that it CAN be used if you use it only once.

This works:

doTitle(func_get_arg(0));

This works also:
doTitle(func_get_arg(1));

So it should not work at all, to be consistent.

Ondrej.

Well, that's true then. But I'm not sure how important this bug is :)

Manual says:

"Note: Because this function depends on the current scope to determine parameter details, it cannot be used as a function parameter. If you must pass this value, assign the results to a variable, and pass the variable."

Dmitry, this script should fail for all of those:

<?php

function doTitle($a = NULL, $b = NULL) {
  print "doTitle: $a, $b\n";
}

function doHead() {
  doTitle(func_num_args());
  doTitle(func_get_arg(0));
  doTitle(func_get_args());
}

doHead("1", "2");

Note: Because this function depends on the current scope to determine parameter details, it may only appear in the first argument to a function.  Thus

myfunc1 (myfunc2 (func_get_arg(1), 7))         OK
myfunc1 (myfunc2 (7, func_get_arg(0)))         Error
myfunc1 (7+func_get_arg(0)+func_get_arg(1))    OK
myfunc2 (func_get_arg(0), func_get_arg(1))     Error

If you must pass this value of func_get_arg() not in the first argument, assign the results to a variable, and pass the variable."

Csaba Gabor from Vienna

Right.
I think this shouldn't be fixed.

I disagree, this function should fail even when used as first argument (also according to docs).

If you allow it to be passed as first argument, but not as second or third, etc., you create only chaos.

It's much more cleaner to let it fail everytime.

Your oppinion makes sense. But I don't see a way to implement this. It is possible to allow use it as any argument or disallow as first argument near the same cost.
I prefer first decision but not for 4.*, 5.*.