use strict;
use warnings;

use Encode qw( decode _utf8_on );
use Devel::Peek;

my $bytes = "\x{C2}A";

{
   open(my $fh, '>:raw', 'temp') or die;
   print $fh $bytes;
}

{
   print STDERR "_utf8_on\n"; 
   print STDERR "--------\n"; 
   open(my $fh, '<:raw', 'temp') or die;
   _utf8_on(my $chars = <$fh>);
   Dump($chars);
}

print STDERR "\n";

{
   print STDERR "binmode ':utf8'\n"; 
   print STDERR "---------------\n"; 
   open(my $fh, '<:utf8', 'temp') or die;
   my $chars = <$fh>;
   Dump($chars);
}

print STDERR "\n";

{
   print STDERR "binmode ':encoding(utf8)'\n";
   print STDERR "-------------------------\n";
   open(my $fh, '<:encoding(utf8)', 'temp') or die;
   my $chars = <$fh>;
   Dump($chars);
}

print STDERR "\n";

{
   print STDERR "decode 'utf8'\n";
   print STDERR "-------------\n";
   my $chars = decode('utf8', $bytes);
   Dump($chars);
}

print STDERR "\n";

{
   print STDERR "decode 'utf-8'\n";
   print STDERR "--------------\n";
   my $chars = decode('utf-8', $bytes);
   Dump($chars);
}

unlink 'temp';
[download]

_utf8_on
--------
SV = PV(0x226154) at 0x1853e20
  REFCNT = 1
  FLAGS = (PADBUSY,PADMY,POK,pPOK,UTF8)
  PV = 0x18307d4 "\302A"\0Malformed UTF-8 character (unexpected non-co
+ntinuation byte 0x41, immediately after start byte 0xc2) in subroutin
+e entry at 688773.pl line 19, <$fh> line 1.
 [UTF8 "\x{0}"]
  CUR = 2
  LEN = 80

binmode ':utf8'
---------------
utf8 "\xC2" does not map to Unicode at 688773.pl line 28, <$fh> line 1
+.
SV = PV(0x226154) at 0x18dcdc4
  REFCNT = 1
  FLAGS = (PADBUSY,PADMY,POK,pPOK,UTF8)
  PV = 0x183083c "\302A"\0Malformed UTF-8 character (unexpected non-co
+ntinuation byte 0x41, immediately after start byte 0xc2) in subroutin
+e entry at 688773.pl line 29, <$fh> line 1.
 [UTF8 "\x{0}"]
  CUR = 2
  LEN = 80

binmode ':encoding(utf8)'
-------------------------
utf8 "\xC2" does not map to Unicode at 688773.pl line 38.
SV = PV(0x22616c) at 0x18dce6c
  REFCNT = 1
  FLAGS = (PADBUSY,PADMY,POK,pPOK,UTF8)
  PV = 0x18f2964 "\\xC2A"\0 [UTF8 "\\xC2A"]
  CUR = 5
  LEN = 80

decode 'utf8'
-------------
SV = PV(0x22616c) at 0x18dce9c
  REFCNT = 1
  FLAGS = (PADBUSY,PADMY,POK,pPOK,UTF8)
  PV = 0x182d0cc "\357\277\275A"\0 [UTF8 "\x{fffd}A"]
  CUR = 4
  LEN = 8

decode 'utf-8'
--------------
SV = PV(0x18d1688) at 0x18dcefc
  REFCNT = 1
  FLAGS = (PADBUSY,PADMY,POK,pPOK,UTF8)
  PV = 0x182ce5c "\357\277\275A"\0 [UTF8 "\x{fffd}A"]
  CUR = 4
  LEN = 8
[download]