in reply to Re^5: Passing a bytestring from Perl to Inline::C as a 2d array
in thread Passing a bytestring from Perl to Inline::C as a 2d array

why even bother with pack()? Pass around something(... a hunk of memory) that is X x Y ints big

That is exactly what he is doing! He's also choosen to initialise it to zeros.

He could also have done that without using pack, say my $buf = chr(0) x ( $x_dimension * $y_dimension * 4 ), but that would then fail if the code is ever ported to a system where the C compiler ints are 64-bit. The way he has choesen to perform the initialisation makes it quite clear what memory represents. A good choice I think.

I am also challenging the need for 'C' in the first place.

You must have a crystal ball then, because I do not see enough information in the OP to give me the confidence to raise such a challenge.

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
RIP PCW It is as I've been saying!(Audio until 20090817)

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Re^7: Passing a bytestring from Perl to Inline::C as a 2d array
by Marshall (Canon) on Nov 14, 2009 at 19:14 UTC
    This should initialize $buf even on a 64 bit system although I don't have one to test with either :-(.

    A 64 bit Perl and 64 bit C should have the same understanding of what an "int" is. But then maybe we get into same stuff like 32 bit Windows running in 16 bit mode kind of stuff! 

     
my $buf = (0) x ( $x_dimension x $y_dimension);

    [download]
    I guess my english is not good enough. Perhaps I should have used "question" instead of "challenge". Sorry if the aggressive tone offended..certainly not my intent. But this is a valid query. The more information provided, the better the result from Monks.
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      This should initialize $buf ... my $buf = (0) x ( $x_dimension x $y_dimension);

      No. It doesn't! Not even close. 

      $x_dimension = 5;
$y_dimension = 4; 
$buf = (0) x ( $x_dimension x $y_dimension); 
print length( $buf ), "'$buf'";;
5555 '0000000000000000000000000000000000000000000000000000000000000000
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      [download]

      And the rest of your post is equally meaningless.

      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
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