Push is a CORE:: subroutine which you can override, please check perlsub

> Printing \$_[0] would print a reference to a reference to an array, not a reference to a reference.

well the constant gets always at runtime a reallocated space, while the arrayref doesn't!!!

here a code that makes it hopefully clearer.

UPDATE: no it doesn't, passing a ref to a literal scalar works as wanted!!! 

use strict;
use warnings;


sub pr {
    print \$_[0]," : ",$_[0],"\t";      # print ref:value of para
}


check(qw/ Scalar 1 /);
check(qw/ Scalarref \1 /);
check(qw/ Array [1,2] /);
check(qw/ Hash  {1,2} /);



sub check {
    my ($_title_,$type) = @_;
    my $_call_ ="pr $type;";
    my $code= <<"__EOC";
    for (1..3) {
    $_call_
        print "\\n\\t"; 
    for (1..3) {
        $_call_
    }
    print "\\n";
    }
__EOC
    print "\n--- $_title_ \n";
    print $code;
    eval $code;
}


__END__

--- Scalar 
    for (1..3) {
    pr 1;
        print "\n\t"; 
    for (1..3) {
        pr 1;
    }
    print "\n";
    }
SCALAR(0x81953b0) : 1    
    SCALAR(0x8190778) : 1    SCALAR(0x8190754) : 1    SCALAR(0x8190778
+) : 1    
SCALAR(0x8190754) : 1    
    SCALAR(0x819076c) : 1    SCALAR(0x8190778) : 1    SCALAR(0x819076c
+) : 1    
SCALAR(0x8190778) : 1    
    SCALAR(0x81953b0) : 1    SCALAR(0x819076c) : 1    SCALAR(0x81953b0
+) : 1    

--- Scalarref 
    for (1..3) {
    pr \1;
        print "\n\t"; 
    for (1..3) {
        pr \1;
    }
    print "\n";
    }
REF(0x8190754) : SCALAR(0x81953ec)    
    REF(0x8190760) : SCALAR(0x8195428)    REF(0x819073c) : SCALAR(0x81
+95428)    REF(0x8190760) : SCALAR(0x8195428)    
REF(0x819073c) : SCALAR(0x81953ec)    
    REF(0x81953b0) : SCALAR(0x8195428)    REF(0x8190760) : SCALAR(0x81
+95428)    REF(0x81953b0) : SCALAR(0x8195428)    
REF(0x8190760) : SCALAR(0x81953ec)    
    REF(0x8190754) : SCALAR(0x8195428)    REF(0x81953b0) : SCALAR(0x81
+95428)    REF(0x8190754) : SCALAR(0x8195428)    

--- Array 
    for (1..3) {
    pr [1,2];
        print "\n\t"; 
    for (1..3) {
        pr [1,2];
    }
    print "\n";
    }
REF(0x8190754) : ARRAY(0x81953c8)    
    REF(0x8190724) : ARRAY(0x819073c)    REF(0x8190724) : ARRAY(0x8190
+73c)    REF(0x8190724) : ARRAY(0x819073c)    
REF(0x8190754) : ARRAY(0x819073c)    
    REF(0x8190724) : ARRAY(0x81953c8)    REF(0x8190724) : ARRAY(0x8195
+3c8)    REF(0x8190724) : ARRAY(0x81953c8)    
REF(0x8190754) : ARRAY(0x81953c8)    
    REF(0x8190724) : ARRAY(0x819073c)    REF(0x8190724) : ARRAY(0x8190
+73c)    REF(0x8190724) : ARRAY(0x819073c)    

--- Hash 
    for (1..3) {
    pr {1,2};
        print "\n\t"; 
    for (1..3) {
        pr {1,2};
    }
    print "\n";
    }
REF(0x81953c8) : HASH(0x8154708)    
    REF(0x8190748) : HASH(0x81953c8)    REF(0x8190748) : HASH(0x81953c
+8)    REF(0x8190748) : HASH(0x81953c8)    
REF(0x8154708) : HASH(0x81953c8)    
    REF(0x8190748) : HASH(0x8154708)    REF(0x8190748) : HASH(0x815470
+8)    REF(0x8190748) : HASH(0x8154708)    
REF(0x81953c8) : HASH(0x8154708)    
    REF(0x8190748) : HASH(0x81953c8)    REF(0x8190748) : HASH(0x81953c
+8)    REF(0x8190748) : HASH(0x81953c8)

[download]

Cheers Rolf

In reply to Re^4: Reference of constants and literals by LanX
in thread Reference of constants and literals by LanX

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