hash keys are read-only but they're not really readonly ... so Scalar::Util::readonly has bug in that it doesn't document the nuances of readonlyness :) 
#!/usr/bin/perl --
use strict; use warnings;
use Devel::Peek qw/ Dump /;
use Readonly;
Readonly::Scalar my $rs => 66;
my %hh = qw/ A B /;
while( my( $k, $v ) = each %hh ){
    Dump( $k );
    Dump( $v );
}
for( 1 ){
    Dump( $_ ); ## the readonliest
}
Dump( $rs );
__END__

[download]
SV = PV(0x3f7b44) at 0x99b8ac
  REFCNT = 1
  FLAGS = (PADMY,POK,FAKE,READONLY,pPOK)
  PV = 0x99ce88 "A"
  CUR = 1
  LEN = 0
SV = PV(0x3f7b4c) at 0xaca8bc
  REFCNT = 1
  FLAGS = (PADMY,POK,pPOK)
  PV = 0xadf504 "B"\0
  CUR = 1
  LEN = 12
SV = IV(0xae0670) at 0xae0674
  REFCNT = 2
  FLAGS = (PADTMP,IOK,READONLY,pIOK)
  IV = 1
SV = PVMG(0xad50e4) at 0x3f9bac
  REFCNT = 1
  FLAGS = (PADMY,GMG,SMG,RMG)
  IV = 0
  NV = 0
  PV = 0
  MAGIC = 0x99402c
    MG_VIRTUAL = &PL_vtbl_packelem
    MG_TYPE = PERL_MAGIC_tiedscalar(q)
    MG_FLAGS = 0x02
      REFCOUNTED
    MG_OBJ = 0x3f9adc
    SV = IV(0x3f9ad8) at 0x3f9adc
      REFCNT = 1
      FLAGS = (ROK)
      RV = 0xad353c
      SV = PVMG(0xad50c4) at 0xad353c
        REFCNT = 1
        FLAGS = (PADMY,OBJECT,IOK,pIOK)
        IV = 66
        NV = 0
        PV = 0
        STASH = 0xacab0c        "Readonly::Scalar"

Oh, and http://perldoc.perl.org/perlapi.html#sv_magic is unreadable ...

http://search.cpan.org/dist/illguts/index.html, redefining Internals::SvREADONLY

In reply to Re: Readonly problems (Devel::Peek, Scalar::Util::readonly bug) by Anonymous Monk
in thread Readonly problems by runrig

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