array copy question

smackdab has asked for the wisdom of the Perl Monks concerning the following question:

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Re: array copy question by Roger (Parson) on Dec 08, 2003 at 22:49 UTC
Yes declaration of array reference has changed in 5.8. The code below will not compile under 5.8: `my @$ra_ret_save = @$ra_ret;` [download] You do not have to declare array refence and copy from another array in two separate steps. You can do in one single step - `my $ra_ret_save = [ @$ra_ret ];` [download] I have created a demo script below - `use strict; use warnings; use Data::Dumper; my $ra_ret = [ qw/ a b c d / ]; print Dumper($ra_ret); my $ra_ret_save = [ @$ra_ret ]; print Dumper($ra_ret_save);` [download] And the output when run from 5.8 and 5.6 - `perl 5.8.0 ---------- $VAR1 = [ 'a', 'b', 'c', 'd' ]; $VAR1 = [ 'a', 'b', 'c', 'd' ]; perl 5.6.1 ---------- $VAR1 = [ 'a', 'b', 'c', 'd' ]; $VAR1 = [ 'a', 'b', 'c', 'd' ];` [download]	[reply] [d/l] [select]
Re: array copy question by Roy Johnson (Monsignor) on Dec 08, 2003 at 22:26 UTC
Just to be clear: the curlies are still not required, but you have to declare the reference (`$ra_ret_save`) separately from dereferencing it. `my $ra_ret_save; @$ra_ret_save = @$ra_ret;` [download] If you really had a jones for doing it all at once: `my $ra_ret_save = [@$ra_ret];` [download] The PerlMonk `tr///` Advocate	[reply] [d/l] [select]
Re: array copy question by duff (Parson) on Dec 08, 2003 at 22:10 UTC
I don't think you are remembering the 5.6 code correctly. Most likely you had `my @array = @{$array_ref};`. If `my @$foo` did work with 5.6 is was a bug and what changed was that bug was fixed. PerlJam	[reply] [d/l] [select]