xref: /openbsd/gnu/usr.bin/perl/lib/overload.t (revision 3d61058a) 
1#!./perl -T
2
3BEGIN {
4    chdir 't' if -d 't';
5    @INC = '../lib';
6    require Config;
7    if (($Config::Config{'extensions'} !~ m!\bList/Util\b!) ){
8	print "1..0 # Skip -- Perl configured without List::Util module\n";
9	exit 0;
10    }
11}
12
13my $no_taint_support = exists($Config::Config{taint_support})
14                     && !$Config::Config{taint_support};
15
16my %skip_fetch_count_when_no_taint = (
17    '<${$ts}> RT57012_OV' => 1,
18    '<use integer; ${$ts}> RT57012_OV' => 1,
19    '<do {&{$ts} for 1,2}> RT57012_OV' => 1,
20    '<use integer; do {&{$ts} for 1,2}> RT57012_OV' => 1,
21    '<*RT57012B = *{$ts}; our $RT57012B> RT57012_OV' => 1,
22    '<use integer; *RT57012B = *{$ts}; our $RT57012B> RT57012_OV' => 1,
23);
24
25sub is_if_taint_supported {
26    my ($got, $expected, $name, @mess) = @_;
27    if ($expected && $no_taint_support) {
28        return skip("your perl was built without taint support");
29    }
30    else {
31        return is($got, $expected, $name, @mess);
32    }
33}
34
35
36package Oscalar;
37use overload (
38				# Anonymous subroutines:
39'+'	=>	sub {new Oscalar $ {$_[0]}+$_[1]},
40'-'	=>	sub {new Oscalar
41		       $_[2]? $_[1]-${$_[0]} : ${$_[0]}-$_[1]},
42'<=>'	=>	sub {new Oscalar
43		       $_[2]? $_[1]-${$_[0]} : ${$_[0]}-$_[1]},
44'cmp'	=>	sub {new Oscalar
45		       $_[2]? ($_[1] cmp ${$_[0]}) : (${$_[0]} cmp $_[1])},
46'*'	=>	sub {new Oscalar ${$_[0]}*$_[1]},
47'/'	=>	sub {new Oscalar
48		       $_[2]? $_[1]/${$_[0]} :
49			 ${$_[0]}/$_[1]},
50'%'	=>	sub {new Oscalar
51		       $_[2]? $_[1]%${$_[0]} : ${$_[0]}%$_[1]},
52'**'	=>	sub {new Oscalar
53		       $_[2]? $_[1]**${$_[0]} : ${$_[0]}-$_[1]},
54
55qw(
56""	stringify
570+	numify)			# Order of arguments insignificant
58);
59
60sub new {
61  my $foo = $_[1];
62  bless \$foo, $_[0];
63}
64
65sub stringify { "${$_[0]}" }
66sub numify { 0 + "${$_[0]}" }	# Not needed, additional overhead
67				# comparing to direct compilation based on
68				# stringify
69
70package main;
71
72$| = 1;
73BEGIN { require './test.pl'; require './charset_tools.pl' }
74plan tests => 5367;
75
76use Scalar::Util qw(tainted);
77
78$a = new Oscalar "087";
79$b= "$a";
80
81is($b, $a);
82is($b, "087");
83is(ref $a, "Oscalar");
84is($a, $a);
85is($a, "087");
86
87$c = $a + 7;
88
89is(ref $c, "Oscalar");
90isnt($c, $a);
91is($c, "94");
92
93$b=$a;
94
95is(ref $a, "Oscalar");
96
97$b++;
98
99is(ref $b, "Oscalar");
100is($a, "087");
101is($b, "88");
102is(ref $a, "Oscalar");
103
104$c=$b;
105$c-=$a;
106
107is(ref $c, "Oscalar");
108is($a, "087");
109is($c, "1");
110is(ref $a, "Oscalar");
111
112$b=1;
113$b+=$a;
114
115is(ref $b, "Oscalar");
116is($a, "087");
117is($b, "88");
118is(ref $a, "Oscalar");
119
120eval q[ package Oscalar; use overload ('++' => sub { $ {$_[0]}++;$_[0] } ) ];
121
122$b=$a;
123
124is(ref $a, "Oscalar");
125
126$b++;
127
128is(ref $b, "Oscalar");
129is($a, "087");
130is($b, "88");
131is(ref $a, "Oscalar");
132
133package Oscalar;
134$dummy=bless \$dummy;		# Now cache of method should be reloaded
135package main;
136
137$b=$a;
138$b++;
139
140is(ref $b, "Oscalar");
141is($a, "087");
142is($b, "88");
143is(ref $a, "Oscalar");
144
145undef $b;			# Destroying updates tables too...
146
147eval q[package Oscalar; use overload ('++' => sub { $ {$_[0]} += 2; $_[0] } ) ];
148
149$b=$a;
150
151is(ref $a, "Oscalar");
152
153$b++;
154
155is(ref $b, "Oscalar");
156is($a, "087");
157is($b, "89");
158is(ref $a, "Oscalar");
159
160package Oscalar;
161$dummy=bless \$dummy;		# Now cache of method should be reloaded
162package main;
163
164$b++;
165
166is(ref $b, "Oscalar");
167is($a, "087");
168is($b, "91");
169is(ref $a, "Oscalar");
170
171$b=$a;
172$b++;
173
174is(ref $b, "Oscalar");
175is($a, "087");
176is($b, "89");
177is(ref $a, "Oscalar");
178
179
180ok($b? 1:0);
181
182eval q[ package Oscalar; use overload ('=' => sub {$main::copies++;
183						   package Oscalar;
184						   local $new=$ {$_[0]};
185						   bless \$new } ) ];
186
187$b=new Oscalar "$a";
188
189is(ref $b, "Oscalar");
190is($a, "087");
191is($b, "087");
192is(ref $a, "Oscalar");
193
194$b++;
195
196is(ref $b, "Oscalar");
197is($a, "087");
198is($b, "89");
199is(ref $a, "Oscalar");
200is($copies, undef);
201
202$b+=1;
203
204is(ref $b, "Oscalar");
205is($a, "087");
206is($b, "90");
207is(ref $a, "Oscalar");
208is($copies, undef);
209
210$b=$a;
211$b+=1;
212
213is(ref $b, "Oscalar");
214is($a, "087");
215is($b, "88");
216is(ref $a, "Oscalar");
217is($copies, undef);
218
219$b=$a;
220$b++;
221
222is(ref $b, "Oscalar");
223is($a, "087");
224is($b, "89");
225is(ref $a, "Oscalar");
226is($copies, 1);
227
228eval q[package Oscalar; use overload ('+=' => sub {$ {$_[0]} += 3*$_[1];
229						   $_[0] } ) ];
230$c=new Oscalar;			# Cause rehash
231
232$b=$a;
233$b+=1;
234
235is(ref $b, "Oscalar");
236is($a, "087");
237is($b, "90");
238is(ref $a, "Oscalar");
239is($copies, 2);
240
241$b+=$b;
242
243is(ref $b, "Oscalar");
244is($b, "360");
245is($copies, 2);
246$b=-$b;
247
248is(ref $b, "Oscalar");
249is($b, "-360");
250is($copies, 2);
251
252$b=abs($b);
253
254is(ref $b, "Oscalar");
255is($b, "360");
256is($copies, 2);
257
258$b=abs($b);
259
260is(ref $b, "Oscalar");
261is($b, "360");
262is($copies, 2);
263
264eval q[package Oscalar;
265       use overload ('x' => sub {new Oscalar ( $_[2] ? "_.$_[1]._" x $ {$_[0]}
266					      : "_.${$_[0]}._" x $_[1])}) ];
267
268$a=new Oscalar "yy";
269$a x= 3;
270is($a, "_.yy.__.yy.__.yy._");
271
272eval q[package Oscalar;
273       use overload ('.' => sub {new Oscalar ( $_[2] ?
274					      "_.$_[1].__.$ {$_[0]}._"
275					      : "_.$ {$_[0]}.__.$_[1]._")}) ];
276
277$a=new Oscalar "xx";
278
279is("b${a}c", "_._.b.__.xx._.__.c._");
280
281# Check inheritance of overloading;
282{
283  package OscalarI;
284  @ISA = 'Oscalar';
285}
286
287$aI = new OscalarI "$a";
288is(ref $aI, "OscalarI");
289is("$aI", "xx");
290is($aI, "xx");
291is("b${aI}c", "_._.b.__.xx._.__.c._");
292
293# Here we test that both "no overload" and
294# blessing to a package update hash
295
296eval "package Oscalar; no overload '.'";
297
298is("b${a}", "bxx");
299$x="1";
300bless \$x, Oscalar;
301is("b${a}c", "bxxc");
302new Oscalar 1;
303is("b${a}c", "bxxc");
304
305# Negative overloading:
306
307$na = eval { ~$a };
308like($@, qr/no method found/);
309
310# Check AUTOLOADING:
311
312*Oscalar::AUTOLOAD =
313  sub { *{"Oscalar::$AUTOLOAD"} = sub {"_!_" . shift() . "_!_"} ;
314	goto &{"Oscalar::$AUTOLOAD"}};
315
316eval "package Oscalar; sub comple; use overload '~' => 'comple'";
317
318$na = eval { ~$a };
319is($@, '');
320
321bless \$x, Oscalar;
322
323$na = eval { ~$a };		# Hash updated
324warn "'$na', $@" if $@;
325ok !$@;
326is($na, '_!_xx_!_');
327
328$na = 0;
329
330$na = eval { ~$aI };
331is($@, '');
332
333bless \$x, OscalarI;
334
335$na = eval { ~$aI };
336print $@;
337
338ok(!$@);
339is($na, '_!_xx_!_');
340
341eval "package Oscalar; sub rshft; use overload '>>' => 'rshft'";
342
343$na = eval { $aI >> 1 };
344is($@, '');
345
346bless \$x, OscalarI;
347
348$na = 0;
349
350$na = eval { $aI >> 1 };
351print $@;
352
353ok(!$@);
354is($na, '_!_xx_!_');
355
356# warn overload::Method($a, '0+'), "\n";
357is(overload::Method($a, '0+'), \&Oscalar::numify);
358is(overload::Method($aI,'0+'), \&Oscalar::numify);
359ok(overload::Overloaded($aI));
360ok(!overload::Overloaded('overload'));
361
362ok(! defined overload::Method($aI, '<<'));
363ok(! defined overload::Method($a, '<'));
364
365like (overload::StrVal($aI), qr/^OscalarI=SCALAR\(0x[\da-fA-F]+\)$/);
366is(overload::StrVal(\$aI), "@{[\$aI]}");
367
368# Check overloading by methods (specified deep in the ISA tree).
369{
370  package OscalarII;
371  @ISA = 'OscalarI';
372  sub Oscalar::lshft {"_<<_" . shift() . "_<<_"}
373  eval "package OscalarI; use overload '<<' => 'lshft', '|' => 'lshft'";
374}
375
376$aaII = "087";
377$aII = \$aaII;
378bless $aII, 'OscalarII';
379bless \$fake, 'OscalarI';		# update the hash
380is(($aI | 3), '_<<_xx_<<_');
381# warn $aII << 3;
382is(($aII << 3), '_<<_087_<<_');
383
384{
385  BEGIN { $int = 7; overload::constant 'integer' => sub {$int++; shift}; }
386  $out = 2**10;
387}
388is($int, 9);
389is($out, 1024);
390is($int, 9);
391{
392  BEGIN { overload::constant 'integer' => sub {$int++; shift()+1}; }
393  eval q{$out = 42};
394}
395is($int, 10);
396is($out, 43);
397
398$foo = 'foo';
399$foo1 = 'f\'o\\o';
400{
401  BEGIN { $q = $qr = 7;
402	  overload::constant 'q' => sub {$q++; push @q, shift, ($_[1] || 'none'); shift},
403			     'qr' => sub {$qr++; push @qr, shift, ($_[1] || 'none'); shift}; }
404  $out = 'foo';
405  $out1 = 'f\'o\\o';
406  $out2 = "a\a$foo,\,";
407  /b\b$foo.\./;
408}
409
410is($out, 'foo');
411is($out, $foo);
412is($out1, 'f\'o\\o');
413is($out1, $foo1);
414is($out2, "a\afoo,\,");
415is("@q", "foo q f'o\\\\o q a\\a qq ,\\, qq");
416is($q, 11);
417is("@qr", "b\\b qq .\\. qq");
418is($qr, 9);
419
420{
421  $_ = '!<b>!foo!<-.>!';
422  BEGIN { overload::constant 'q' => sub {push @q1, shift, ($_[1] || 'none'); "_<" . (shift) . ">_"},
423			     'qr' => sub {push @qr1, shift, ($_[1] || 'none'); "!<" . (shift) . ">!"}; }
424  $out = 'foo';
425  $out1 = 'f\'o\\o';
426  $out2 = "a\a$foo,\,";
427  $res = /b\b$foo.\./;
428  $a = <<EOF;
429oups
430EOF
431  $b = <<'EOF';
432oups1
433EOF
434  $c = bareword;
435  m'try it';
436  s'first part'second part';
437  s/yet another/tail here/;
438  tr/A-Z/a-z/;
439}
440
441is($out, '_<foo>_');
442is($out1, '_<f\'o\\o>_');
443is($out2, "_<a\a>_foo_<,\,>_");
444is("@q1", "foo q f'o\\\\o q a\\a qq ,\\, qq oups
445 qq oups1
446 q second part q tail here s A-Z tr a-z tr");
447is("@qr1", "b\\b qq .\\. qq try it q first part q yet another qq");
448is($res, 1);
449is($a, "_<oups
450>_");
451is($b, "_<oups1
452>_");
453is($c, "bareword");
454
455{
456  package symbolic;		# Primitive symbolic calculator
457  use overload nomethod => \&wrap, '""' => \&str, '0+' => \&num,
458      '=' => \&cpy, '++' => \&inc, '--' => \&dec;
459
460  sub new { shift; bless ['n', @_] }
461  sub cpy {
462    my $self = shift;
463    bless [@$self], ref $self;
464  }
465  sub inc { $_[0] = bless ['++', $_[0], 1]; }
466  sub dec { $_[0] = bless ['--', $_[0], 1]; }
467  sub wrap {
468    my ($obj, $other, $inv, $meth) = @_;
469    if ($meth eq '++' or $meth eq '--') {
470      @$obj = ($meth, (bless [@$obj]), 1); # Avoid circular reference
471      return $obj;
472    }
473    ($obj, $other) = ($other, $obj) if $inv;
474    bless [$meth, $obj, $other];
475  }
476  sub str {
477    my ($meth, $a, $b) = @{+shift};
478    $a = 'u' unless defined $a;
479    if (defined $b) {
480      "[$meth $a $b]";
481    } else {
482      "[$meth $a]";
483    }
484  }
485  my %subr = ( 'n' => sub {$_[0]} );
486  foreach my $op (split " ", $overload::ops{with_assign}) {
487    $subr{$op} = $subr{"$op="} = eval "sub {shift() $op shift()}";
488  }
489  my @bins = qw(binary 3way_comparison num_comparison str_comparison);
490  foreach my $op (split " ", "@overload::ops{ @bins }") {
491    $subr{$op} = eval "sub {shift() $op shift()}";
492  }
493  foreach my $op (split " ", "@overload::ops{qw(unary func)}") {
494    $subr{$op} = eval "sub {$op shift()}";
495  }
496  $subr{'++'} = $subr{'+'};
497  $subr{'--'} = $subr{'-'};
498
499  sub num {
500    my ($meth, $a, $b) = @{+shift};
501    my $subr = $subr{$meth}
502      or die "Do not know how to ($meth) in symbolic";
503    $a = $a->num if ref $a eq __PACKAGE__;
504    $b = $b->num if ref $b eq __PACKAGE__;
505    $subr->($a,$b);
506  }
507  sub TIESCALAR { my $pack = shift; $pack->new(@_) }
508  sub FETCH { shift }
509  sub nop {  }		# Around a bug
510  sub vars { my $p = shift; tie($_, $p), $_->nop foreach @_; }
511  sub STORE {
512    my $obj = shift;
513    $#$obj = 1;
514    $obj->[1] = shift;
515  }
516}
517
518{
519  my $foo = new symbolic 11;
520  my $baz = $foo++;
521  is((sprintf "%d", $foo), '12');
522  is((sprintf "%d", $baz), '11');
523  my $bar = $foo;
524  $baz = ++$foo;
525  is((sprintf "%d", $foo), '13');
526  is((sprintf "%d", $bar), '12');
527  is((sprintf "%d", $baz), '13');
528  my $ban = $foo;
529  $baz = ($foo += 1);
530  is((sprintf "%d", $foo), '14');
531  is((sprintf "%d", $bar), '12');
532  is((sprintf "%d", $baz), '14');
533  is((sprintf "%d", $ban), '13');
534  $baz = 0;
535  $baz = $foo++;
536  is((sprintf "%d", $foo), '15');
537  is((sprintf "%d", $baz), '14');
538  is("$foo", '[++ [+= [++ [++ [n 11] 1] 1] 1] 1]');
539}
540
541{
542  my $iter = new symbolic 2;
543  my $side = new symbolic 1;
544  my $cnt = $iter;
545
546  while ($cnt) {
547    $cnt = $cnt - 1;		# The "simple" way
548    $side = (sqrt(1 + $side**2) - 1)/$side;
549  }
550  my $pi = $side*(2**($iter+2));
551  is("$side", '[/ [- [sqrt [+ 1 [** [/ [- [sqrt [+ 1 [** [n 1] 2]]] 1] [n 1]] 2]]] 1] [/ [- [sqrt [+ 1 [** [n 1] 2]]] 1] [n 1]]]');
552  is((sprintf "%f", $pi), '3.182598');
553}
554
555{
556  my $iter = new symbolic 2;
557  my $side = new symbolic 1;
558  my $cnt = $iter;
559
560  while ($cnt--) {
561    $side = (sqrt(1 + $side**2) - 1)/$side;
562  }
563  my $pi = $side*(2**($iter+2));
564  is("$side", '[/ [- [sqrt [+ 1 [** [/ [- [sqrt [+ 1 [** [n 1] 2]]] 1] [n 1]] 2]]] 1] [/ [- [sqrt [+ 1 [** [n 1] 2]]] 1] [n 1]]]');
565  is((sprintf "%f", $pi), '3.182598');
566}
567
568{
569  my ($a, $b);
570  symbolic->vars($a, $b);
571  my $c = sqrt($a**2 + $b**2);
572  $a = 3; $b = 4;
573  is((sprintf "%d", $c), '5');
574  $a = 12; $b = 5;
575  is((sprintf "%d", $c), '13');
576}
577
578{
579  package symbolic1;		# Primitive symbolic calculator
580  # Mutator inc/dec
581  use overload nomethod => \&wrap, '""' => \&str, '0+' => \&num, '=' => \&cpy;
582
583  sub new { shift; bless ['n', @_] }
584  sub cpy {
585    my $self = shift;
586    bless [@$self], ref $self;
587  }
588  sub wrap {
589    my ($obj, $other, $inv, $meth) = @_;
590    if ($meth eq '++' or $meth eq '--') {
591      @$obj = ($meth, (bless [@$obj]), 1); # Avoid circular reference
592      return $obj;
593    }
594    ($obj, $other) = ($other, $obj) if $inv;
595    bless [$meth, $obj, $other];
596  }
597  sub str {
598    my ($meth, $a, $b) = @{+shift};
599    $a = 'u' unless defined $a;
600    if (defined $b) {
601      "[$meth $a $b]";
602    } else {
603      "[$meth $a]";
604    }
605  }
606  my %subr = ( 'n' => sub {$_[0]} );
607  foreach my $op (split " ", $overload::ops{with_assign}) {
608    $subr{$op} = $subr{"$op="} = eval "sub {shift() $op shift()}";
609  }
610  my @bins = qw(binary 3way_comparison num_comparison str_comparison);
611  foreach my $op (split " ", "@overload::ops{ @bins }") {
612    $subr{$op} = eval "sub {shift() $op shift()}";
613  }
614  foreach my $op (split " ", "@overload::ops{qw(unary func)}") {
615    $subr{$op} = eval "sub {$op shift()}";
616  }
617  $subr{'++'} = $subr{'+'};
618  $subr{'--'} = $subr{'-'};
619
620  sub num {
621    my ($meth, $a, $b) = @{+shift};
622    my $subr = $subr{$meth}
623      or die "Do not know how to ($meth) in symbolic";
624    $a = $a->num if ref $a eq __PACKAGE__;
625    $b = $b->num if ref $b eq __PACKAGE__;
626    $subr->($a,$b);
627  }
628  sub TIESCALAR { my $pack = shift; $pack->new(@_) }
629  sub FETCH { shift }
630  sub vars { my $p = shift; tie($_, $p) foreach @_; }
631  sub STORE {
632    my $obj = shift;
633    $#$obj = 1;
634    $obj->[1] = shift;
635  }
636}
637
638{
639  my $foo = new symbolic1 11;
640  my $baz = $foo++;
641  is((sprintf "%d", $foo), '12');
642  is((sprintf "%d", $baz), '11');
643  my $bar = $foo;
644  $baz = ++$foo;
645  is((sprintf "%d", $foo), '13');
646  is((sprintf "%d", $bar), '12');
647  is((sprintf "%d", $baz), '13');
648  my $ban = $foo;
649  $baz = ($foo += 1);
650  is((sprintf "%d", $foo), '14');
651  is((sprintf "%d", $bar), '12');
652  is((sprintf "%d", $baz), '14');
653  is((sprintf "%d", $ban), '13');
654  $baz = 0;
655  $baz = $foo++;
656  is((sprintf "%d", $foo), '15');
657  is((sprintf "%d", $baz), '14');
658  is("$foo", '[++ [+= [++ [++ [n 11] 1] 1] 1] 1]');
659}
660
661{
662  my $iter = new symbolic1 2;
663  my $side = new symbolic1 1;
664  my $cnt = $iter;
665
666  while ($cnt) {
667    $cnt = $cnt - 1;		# The "simple" way
668    $side = (sqrt(1 + $side**2) - 1)/$side;
669  }
670  my $pi = $side*(2**($iter+2));
671  is("$side", '[/ [- [sqrt [+ 1 [** [/ [- [sqrt [+ 1 [** [n 1] 2]]] 1] [n 1]] 2]]] 1] [/ [- [sqrt [+ 1 [** [n 1] 2]]] 1] [n 1]]]');
672  is((sprintf "%f", $pi), '3.182598');
673}
674
675{
676  my $iter = new symbolic1 2;
677  my $side = new symbolic1 1;
678  my $cnt = $iter;
679
680  while ($cnt--) {
681    $side = (sqrt(1 + $side**2) - 1)/$side;
682  }
683  my $pi = $side*(2**($iter+2));
684  is("$side", '[/ [- [sqrt [+ 1 [** [/ [- [sqrt [+ 1 [** [n 1] 2]]] 1] [n 1]] 2]]] 1] [/ [- [sqrt [+ 1 [** [n 1] 2]]] 1] [n 1]]]');
685  is((sprintf "%f", $pi), '3.182598');
686}
687
688{
689  my ($a, $b);
690  symbolic1->vars($a, $b);
691  my $c = sqrt($a**2 + $b**2);
692  $a = 3; $b = 4;
693  is((sprintf "%d", $c), '5');
694  $a = 12; $b = 5;
695  is((sprintf "%d", $c), '13');
696}
697
698{
699  package two_face;		# Scalars with separate string and
700                                # numeric values.
701  sub new { my $p = shift; bless [@_], $p }
702  use overload '""' => \&str, '0+' => \&num, fallback => 1;
703  sub num {shift->[1]}
704  sub str {shift->[0]}
705}
706
707{
708  my $seven = new two_face ("vii", 7);
709  is((sprintf "seven=$seven, seven=%d, eight=%d", $seven, $seven+1),
710	'seven=vii, seven=7, eight=8');
711  is(scalar ($seven =~ /i/), '1');
712}
713
714{
715  package sorting;
716  use overload 'cmp' => \&comp;
717  sub new { my ($p, $v) = @_; bless \$v, $p }
718  sub comp { my ($x,$y) = @_; ($$x * 3 % 10) <=> ($$y * 3 % 10) or $$x cmp $$y }
719}
720{
721  my @arr = map sorting->new($_), 0..12;
722  my @sorted1 = sort @arr;
723  my @sorted2 = map $$_, @sorted1;
724  is("@sorted2", '0 10 7 4 1 11 8 5 12 2 9 6 3');
725}
726{
727  package iterator;
728  use overload '<>' => \&iter;
729  sub new { my ($p, $v) = @_; bless \$v, $p }
730  sub iter { my ($x) = @_; return undef if $$x < 0; return $$x--; }
731}
732
733{
734  my $iter = iterator->new(5);
735  my $acc = '';
736  my $out;
737  $acc .= " $out" while $out = <${iter}>;
738  is($acc, ' 5 4 3 2 1 0');
739  $iter = iterator->new(5);
740  is(scalar <${iter}>, '5');
741  $acc = '';
742  $acc .= " $out" while $out = <$iter>;
743  is($acc, ' 4 3 2 1 0');
744}
745{
746  package deref;
747  use overload '%{}' => \&hderef, '&{}' => \&cderef,
748    '*{}' => \&gderef, '${}' => \&sderef, '@{}' => \&aderef;
749  sub new { my ($p, $v) = @_; bless \$v, $p }
750  sub deref {
751    my ($self, $key) = (shift, shift);
752    my $class = ref $self;
753    bless $self, 'deref::dummy'; # Disable overloading of %{}
754    my $out = $self->{$key};
755    bless $self, $class;	# Restore overloading
756    $out;
757  }
758  sub hderef {shift->deref('h')}
759  sub aderef {shift->deref('a')}
760  sub cderef {shift->deref('c')}
761  sub gderef {shift->deref('g')}
762  sub sderef {shift->deref('s')}
763}
764{
765  my $deref = bless { h => { foo => 5 , fake => 23 },
766		      c => sub {return shift() + 34},
767		      's' => \123,
768		      a => [11..13],
769		      g => \*srt,
770		    }, 'deref';
771  # Hash:
772  my @cont = sort %$deref;
773  if ("\t" eq "\011") { # ASCII
774      is("@cont", '23 5 fake foo');
775  }
776  else {                # EBCDIC alpha-numeric sort order
777      is("@cont", 'fake foo 23 5');
778  }
779  my @keys = sort keys %$deref;
780  is("@keys", 'fake foo');
781  my @val = sort values %$deref;
782  is("@val", '23 5');
783  is($deref->{foo}, 5);
784  is(defined $deref->{bar}, '');
785  my $key;
786  @keys = ();
787  push @keys, $key while $key = each %$deref;
788  @keys = sort @keys;
789  is("@keys", 'fake foo');
790  is(exists $deref->{bar}, '');
791  is(exists $deref->{foo}, 1);
792  # Code:
793  is($deref->(5), 39);
794  is(&$deref(6), 40);
795  sub xxx_goto { goto &$deref }
796  is(xxx_goto(7), 41);
797  my $srt = bless { c => sub {$b <=> $a}
798		  }, 'deref';
799  *srt = \&$srt;
800  my @sorted = sort srt 11, 2, 5, 1, 22;
801  is("@sorted", '22 11 5 2 1');
802  # Scalar
803  is($$deref, 123);
804  # Code
805  @sorted = sort $srt 11, 2, 5, 1, 22;
806  is("@sorted", '22 11 5 2 1');
807  # Array
808  is("@$deref", '11 12 13');
809  is($#$deref, '2');
810  my $l = @$deref;
811  is($l, 3);
812  is($deref->[2], '13');
813  $l = pop @$deref;
814  is($l, 13);
815  $l = 1;
816  is($deref->[$l], '12');
817  # Repeated dereference
818  my $double = bless { h => $deref,
819		     }, 'deref';
820  is($double->{foo}, 5);
821}
822
823{
824  package two_refs;
825  use overload '%{}' => \&gethash, '@{}' => sub { ${shift()} };
826  sub new {
827    my $p = shift;
828    bless \ [@_], $p;
829  }
830  sub gethash {
831    my %h;
832    my $self = shift;
833    tie %h, ref $self, $self;
834    \%h;
835  }
836
837  sub TIEHASH { my $p = shift; bless \ shift, $p }
838  my %fields;
839  my $i = 0;
840  $fields{$_} = $i++ foreach qw{zero one two three};
841  sub STORE {
842    my $self = ${shift()};
843    my $key = $fields{shift()};
844    defined $key or die "Out of band access";
845    $$self->[$key] = shift;
846  }
847  sub FETCH {
848    my $self = ${shift()};
849    my $key = $fields{shift()};
850    defined $key or die "Out of band access";
851    $$self->[$key];
852  }
853}
854
855my $bar = new two_refs 3,4,5,6;
856$bar->[2] = 11;
857is($bar->{two}, 11);
858$bar->{three} = 13;
859is($bar->[3], 13);
860
861{
862  package two_refs_o;
863  @ISA = ('two_refs');
864}
865
866$bar = new two_refs_o 3,4,5,6;
867$bar->[2] = 11;
868is($bar->{two}, 11);
869$bar->{three} = 13;
870is($bar->[3], 13);
871
872{
873  package two_refs1;
874  use overload '%{}' => sub { ${shift()}->[1] },
875               '@{}' => sub { ${shift()}->[0] };
876  sub new {
877    my $p = shift;
878    my $a = [@_];
879    my %h;
880    tie %h, $p, $a;
881    bless \ [$a, \%h], $p;
882  }
883  sub gethash {
884    my %h;
885    my $self = shift;
886    tie %h, ref $self, $self;
887    \%h;
888  }
889
890  sub TIEHASH { my $p = shift; bless \ shift, $p }
891  my %fields;
892  my $i = 0;
893  $fields{$_} = $i++ foreach qw{zero one two three};
894  sub STORE {
895    my $a = ${shift()};
896    my $key = $fields{shift()};
897    defined $key or die "Out of band access";
898    $a->[$key] = shift;
899  }
900  sub FETCH {
901    my $a = ${shift()};
902    my $key = $fields{shift()};
903    defined $key or die "Out of band access";
904    $a->[$key];
905  }
906}
907
908$bar = new two_refs_o 3,4,5,6;
909$bar->[2] = 11;
910is($bar->{two}, 11);
911$bar->{three} = 13;
912is($bar->[3], 13);
913
914{
915  package two_refs1_o;
916  @ISA = ('two_refs1');
917}
918
919$bar = new two_refs1_o 3,4,5,6;
920$bar->[2] = 11;
921is($bar->{two}, 11);
922$bar->{three} = 13;
923is($bar->[3], 13);
924
925{
926  package B;
927  use overload bool => sub { ${+shift} };
928}
929
930my $aaa;
931{ my $bbbb = 0; $aaa = bless \$bbbb, B }
932
933is !$aaa, 1;
934
935unless ($aaa) {
936  pass();
937} else {
938  fail();
939}
940
941# check that overload isn't done twice by join
942{ my $c = 0;
943  package Join;
944  use overload '""' => sub { $c++ };
945  my $x = join '', bless([]), 'pq', bless([]);
946  main::is $x, '0pq1';
947};
948
949# Test module-specific warning
950{
951    # check the Odd number of arguments for overload::constant warning
952    my $a = "" ;
953    local $SIG{__WARN__} = sub {$a = $_[0]} ;
954    $x = eval ' overload::constant "integer" ; ' ;
955    is($a, "");
956    use warnings 'overload' ;
957    $x = eval ' overload::constant "integer" ; ' ;
958    like($a, qr/^Odd number of arguments for overload::constant at/);
959}
960
961{
962    # check the '$_[0]' is not an overloadable type warning
963    my $a = "" ;
964    local $SIG{__WARN__} = sub {$a = $_[0]} ;
965    $x = eval ' overload::constant "fred" => sub {} ; ' ;
966    is($a, "");
967    use warnings 'overload' ;
968    $x = eval ' overload::constant "fred" => sub {} ; ' ;
969    like($a, qr/^'fred' is not an overloadable type at/);
970}
971
972{
973    # check the '$_[1]' is not a code reference warning
974    my $a = "" ;
975    local $SIG{__WARN__} = sub {$a = $_[0]} ;
976    $x = eval ' overload::constant "integer" => 1; ' ;
977    is($a, "");
978    use warnings 'overload' ;
979    $x = eval ' overload::constant "integer" => 1; ' ;
980    like($a, qr/^'1' is not a code reference at/);
981}
982
983{
984    # check the invalid argument warning [perl #74098]
985    my $a = "" ;
986    local $SIG{__WARN__} = sub {$a = $_[0]} ;
987    $x = eval ' use overload "~|_|~" => sub{} ' ;
988    eval ' no overload "~|_|~" ' ;
989    is($a, "");
990    use warnings 'overload' ;
991    $x = eval ' use overload "~|_|~" => sub{} ' ;
992    like($a, qr/^overload arg '~\|_\|~' is invalid at \(eval \d+\) line /,
993	'invalid arg warning');
994    undef $a;
995    eval ' no overload "~|_|~" ' ;
996    like($a, qr/^overload arg '~\|_\|~' is invalid at \(eval \d+\) line /,
997	'invalid arg warning');
998}
999
1000{
1001  my $c = 0;
1002  package ov_int1;
1003  use overload '""'    => sub { 3+shift->[0] },
1004               '0+'    => sub { 10+shift->[0] },
1005               'int'   => sub { 100+shift->[0] };
1006  sub new {my $p = shift; bless [shift], $p}
1007
1008  package ov_int2;
1009  use overload '""'    => sub { 5+shift->[0] },
1010               '0+'    => sub { 30+shift->[0] },
1011               'int'   => sub { 'ov_int1'->new(1000+shift->[0]) };
1012  sub new {my $p = shift; bless [shift], $p}
1013
1014  package noov_int;
1015  use overload '""'    => sub { 2+shift->[0] },
1016               '0+'    => sub { 9+shift->[0] };
1017  sub new {my $p = shift; bless [shift], $p}
1018
1019  package main;
1020
1021  my $x = new noov_int 11;
1022  my $int_x = int $x;
1023  main::is("$int_x", 20);
1024  $x = new ov_int1 31;
1025  $int_x = int $x;
1026  main::is("$int_x", 131);
1027  $x = new ov_int2 51;
1028  $int_x = int $x;
1029  main::is("$int_x", 1054);
1030}
1031
1032# make sure that we don't infinitely recurse
1033{
1034  my $c = 0;
1035  package Recurse;
1036  use overload '""'    => sub { shift },
1037               '0+'    => sub { shift },
1038               'bool'  => sub { shift },
1039               fallback => 1;
1040  my $x = bless([]);
1041  # For some reason beyond me these have to be oks rather than likes.
1042  main::ok("$x" =~ /Recurse=ARRAY/);
1043  main::ok($x);
1044  main::ok($x+0 =~ qr/Recurse=ARRAY/);
1045}
1046
1047# BugID 20010422.003 (#6872)
1048package Foo;
1049
1050use overload
1051  'bool' => sub { return !$_[0]->is_zero() || undef; }
1052;
1053
1054sub is_zero
1055  {
1056  my $self = shift;
1057  return $self->{var} == 0;
1058  }
1059
1060sub new
1061  {
1062  my $class = shift;
1063  my $self =  {};
1064  $self->{var} = shift;
1065  bless $self,$class;
1066  }
1067
1068package main;
1069
1070use strict;
1071
1072my $r = Foo->new(8);
1073$r = Foo->new(0);
1074
1075is(($r || 0), 0);
1076
1077package utf8_o;
1078
1079use overload
1080  '""'  =>  sub { return $_[0]->{var}; }
1081  ;
1082
1083sub new
1084  {
1085    my $class = shift;
1086    my $self =  {};
1087    $self->{var} = shift;
1088    bless $self,$class;
1089  }
1090
1091package main;
1092
1093
1094my $utfvar = new utf8_o 200.2.1;
1095is("$utfvar", 200.2.1); # 223 - stringify
1096is("a$utfvar", "a".200.2.1); # 224 - overload via sv_2pv_flags
1097
1098# 225..227 -- more %{} tests.  Hangs in 5.6.0, okay in later releases.
1099# Basically this example implements strong encapsulation: if Hderef::import()
1100# were to eval the overload code in the caller's namespace, the privatisation
1101# would be quite transparent.
1102package Hderef;
1103use overload '%{}' => sub { caller(0) eq 'Foo' ? $_[0] : die "zap" };
1104package Foo;
1105@Foo::ISA = 'Hderef';
1106sub new { bless {}, shift }
1107sub xet { @_ == 2 ? $_[0]->{$_[1]} :
1108	  @_ == 3 ? ($_[0]->{$_[1]} = $_[2]) : undef }
1109package main;
1110my $a = Foo->new;
1111$a->xet('b', 42);
1112is ($a->xet('b'), 42);
1113ok (!defined eval { $a->{b} });
1114like ($@, qr/zap/);
1115
1116{
1117   package t229;
1118   use overload '='  => sub { 42 },
1119                '++' => sub { my $x = ${$_[0]}; $_[0] };
1120   sub new { my $x = 42; bless \$x }
1121
1122   my $warn;
1123   {
1124     local $SIG{__WARN__} = sub { $warn++ };
1125      my $x = t229->new;
1126      my $y = $x;
1127      eval { $y++ };
1128   }
1129   main::ok (!$warn);
1130}
1131
1132{
1133    my ($int, $out1, $out2);
1134    {
1135        BEGIN { $int = 0; overload::constant 'integer' => sub {$int++; 17}; }
1136        $out1 = 0;
1137        $out2 = 1;
1138    }
1139    is($int,  2,  "#24313");	# 230
1140    is($out1, 17, "#24313");	# 231
1141    is($out2, 17, "#24313");	# 232
1142}
1143
1144{
1145    package perl31793;
1146    use overload cmp => sub { 0 };
1147    package perl31793_fb;
1148    use overload cmp => sub { 0 }, fallback => 1;
1149    package main;
1150    my $o  = bless [], 'perl31793';
1151    my $of = bless [], 'perl31793_fb';
1152    my $no = bless [], 'no_overload';
1153    like(overload::StrVal(\"scalar"), qr/^SCALAR\(0x[0-9a-f]+\)$/);
1154    like(overload::StrVal([]),        qr/^ARRAY\(0x[0-9a-f]+\)$/);
1155    like(overload::StrVal({}),        qr/^HASH\(0x[0-9a-f]+\)$/);
1156    like(overload::StrVal(sub{1}),    qr/^CODE\(0x[0-9a-f]+\)$/);
1157    like(overload::StrVal(\*GLOB),    qr/^GLOB\(0x[0-9a-f]+\)$/);
1158    like(overload::StrVal(\$o),       qr/^REF\(0x[0-9a-f]+\)$/);
1159    like(overload::StrVal(qr/a/),     qr/^Regexp=REGEXP\(0x[0-9a-f]+\)$/);
1160    like(overload::StrVal($o),        qr/^perl31793=ARRAY\(0x[0-9a-f]+\)$/);
1161    like(overload::StrVal($of),       qr/^perl31793_fb=ARRAY\(0x[0-9a-f]+\)$/);
1162    like(overload::StrVal($no),       qr/^no_overload=ARRAY\(0x[0-9a-f]+\)$/);
1163}
1164
1165{
1166    package Numify;
1167    use overload (qw(0+ numify fallback 1));
1168
1169    sub new {
1170	my $val = $_[1];
1171	bless \$val, $_[0];
1172    }
1173
1174    sub numify { ${$_[0]} }
1175}
1176
1177# These all check that overloaded values, rather than reference addresses,
1178# are what are getting tested.
1179my ($two, $one, $un, $deux) = map {new Numify $_} 2, 1, 1, 2;
1180my ($ein, $zwei) = (1, 2);
1181
1182my %map = (one => 1, un => 1, ein => 1, deux => 2, two => 2, zwei => 2);
1183foreach my $op (qw(<=> == != < <= > >=)) {
1184    foreach my $l (keys %map) {
1185	foreach my $r (keys %map) {
1186	    my $ocode = "\$$l $op \$$r";
1187	    my $rcode = "$map{$l} $op $map{$r}";
1188
1189	    my $got = eval $ocode;
1190	    die if $@;
1191	    my $expect = eval $rcode;
1192	    die if $@;
1193	    is ($got, $expect, $ocode) or print "# $rcode\n";
1194	}
1195    }
1196}
1197{
1198    # check that overloading works in regexes
1199    {
1200	package Foo493;
1201	use overload
1202	    '""' => sub { "^$_[0][0]\$" },
1203	    '.'  => sub {
1204		    bless [
1205			     $_[2]
1206			    ? (ref $_[1] ? $_[1][0] : $_[1]) . ':' .$_[0][0]
1207			    : $_[0][0] . ':' . (ref $_[1] ? $_[1][0] : $_[1])
1208		    ], 'Foo493'
1209			};
1210    }
1211
1212    my $a = bless [ "a" ], 'Foo493';
1213    like('a', qr/$a/);
1214    like('x:a', qr/x$a/);
1215    like('x:a:=', qr/x$a=$/);
1216    like('x:a:a:=', qr/x$a$a=$/);
1217
1218}
1219
1220{
1221    {
1222        package QRonly;
1223        use overload qr => sub { qr/x/ }, fallback => 1;
1224    }
1225    {
1226        my $x = bless [], "QRonly";
1227
1228        # like tries to be too clever, and decides that $x-stringified
1229        # doesn't look like a regex
1230        ok("x" =~ $x, "qr-only matches");
1231        ok("y" !~ $x, "qr-only doesn't match what it shouldn't");
1232        ok("x" =~ /^(??{$x})$/, "qr-only with ?? matches");
1233        ok("y" !~ /^(??{$x})$/, "qr-only with ?? doesn't match what it shouldn't");
1234        ok("xx" =~ /x$x/, "qr-only matches with concat");
1235        like("$x", qr/^QRonly=ARRAY/, "qr-only doesn't have string overload");
1236
1237        my $qr = bless qr/y/, "QRonly";
1238        ok("x" =~ $qr, "qr with qr-overload uses overload");
1239        ok("y" !~ $qr, "qr with qr-overload uses overload");
1240	ok("x" =~ /^(??{$qr})$/, "qr with qr-overload with ?? uses overload");
1241	ok("y" !~ /^(??{$qr})$/, "qr with qr-overload with ?? uses overload");
1242        is("$qr", "".qr/y/, "qr with qr-overload stringify");
1243
1244        my $rx = $$qr;
1245        ok("y" =~ $rx, "bare rx with qr-overload doesn't overload match");
1246        ok("x" !~ $rx, "bare rx with qr-overload doesn't overload match");
1247        ok("y" =~ /^(??{$rx})$/, "bare rx with qr-overload with ?? doesn't overload match");
1248        ok("x" !~ /^(??{$rx})$/, "bare rx with qr-overload with ?? doesn't overload match");
1249        is("$rx", "".qr/y/, "bare rx with qr-overload stringify");
1250    }
1251    {
1252        package QRandSTR;
1253        use overload qr => sub { qr/x/ }, q/""/ => sub { "y" };
1254    }
1255    {
1256        my $x = bless [], "QRandSTR";
1257        ok("x" =~ $x, "qr+str uses qr for match");
1258        ok("y" !~ $x, "qr+str uses qr for match");
1259        ok("xx" =~ /x$x/, "qr+str uses qr for match with concat");
1260        is("$x", "y", "qr+str uses str for stringify");
1261
1262        my $qr = bless qr/z/, "QRandSTR";
1263        is("$qr", "y", "qr with qr+str uses str for stringify");
1264        ok("xx" =~ /x$x/, "qr with qr+str uses qr for match");
1265
1266        my $rx = $$qr;
1267        ok("z" =~ $rx, "bare rx with qr+str doesn't overload match");
1268        is("$rx", "".qr/z/, "bare rx with qr+str doesn't overload stringify");
1269    }
1270    {
1271        package QRany;
1272        use overload qr => sub { $_[0]->(@_) };
1273
1274        package QRself;
1275        use overload qr => sub { $_[0] };
1276    }
1277    {
1278        my $rx = bless sub { ${ qr/x/ } }, "QRany";
1279        ok("x" =~ $rx, "qr overload accepts a bare rx");
1280        ok("y" !~ $rx, "qr overload accepts a bare rx");
1281
1282        my $str = bless sub { "x" }, "QRany";
1283        ok(!eval { "x" =~ $str }, "qr overload doesn't accept a string");
1284        like($@, qr/^Overloaded qr did not return a REGEXP/, "correct error");
1285
1286        my $oqr = bless qr/z/, "QRandSTR";
1287        my $oqro = bless sub { $oqr }, "QRany";
1288        ok("z" =~ $oqro, "qr overload doesn't recurse");
1289
1290        my $qrs = bless qr/z/, "QRself";
1291        ok("z" =~ $qrs, "qr overload can return self");
1292    }
1293    {
1294        package STRonly;
1295        use overload q/""/ => sub { "x" };
1296
1297        package STRonlyFB;
1298        use overload q/""/ => sub { "x" }, fallback => 1;
1299    }
1300    {
1301        my $fb = bless [], "STRonlyFB";
1302        ok("x" =~ $fb, "qr falls back to \"\"");
1303        ok("y" !~ $fb, "qr falls back to \"\"");
1304
1305        my $nofb = bless [], "STRonly";
1306        ok("x" =~ $nofb, "qr falls back even without fallback");
1307        ok("y" !~ $nofb, "qr falls back even without fallback");
1308    }
1309}
1310
1311{
1312    my $twenty_three = 23;
1313    # Check that constant overloading propagates into evals
1314    BEGIN { overload::constant integer => sub { 23 } }
1315    is(eval "17", $twenty_three);
1316}
1317
1318{
1319    # Check readonliness of constants, whether shared hash key
1320    # scalars or no (brought up in bug #109744)
1321    BEGIN { overload::constant integer => sub { "main" }; }
1322    eval { ${\5} = 'whatever' };
1323    like $@, qr/^Modification of a read-only value attempted at /,
1324	'constant overloading makes read-only constants';
1325    BEGIN { overload::constant integer => sub { __PACKAGE__ }; }
1326    eval { ${\5} = 'whatever' };
1327    like $@, qr/^Modification of a read-only value attempted at /,
1328	'... even with shared hash key scalars';
1329}
1330
1331{
1332    package Sklorsh;
1333    use overload
1334	bool     => sub { shift->is_cool };
1335
1336    sub is_cool {
1337	$_[0]->{name} eq 'cool';
1338    }
1339
1340    sub delete {
1341	undef %{$_[0]};
1342	bless $_[0], 'Brap';
1343	return 1;
1344    }
1345
1346    sub delete_with_self {
1347	my $self = shift;
1348	undef %$self;
1349	bless $self, 'Brap';
1350	return 1;
1351    }
1352
1353    package Brap;
1354
1355    1;
1356
1357    package main;
1358
1359    my $obj;
1360    $obj = bless {name => 'cool'}, 'Sklorsh';
1361    $obj->delete;
1362    ok(eval {if ($obj) {1}; 1}, $@ || 'reblessed into nonexistent namespace');
1363
1364    $obj = bless {name => 'cool'}, 'Sklorsh';
1365    $obj->delete_with_self;
1366    ok (eval {if ($obj) {1}; 1}, $@);
1367
1368    my $a = $b = {name => 'hot'};
1369    bless $b, 'Sklorsh';
1370    is(ref $a, 'Sklorsh');
1371    is(ref $b, 'Sklorsh');
1372    ok(!$b, "Expect overloaded boolean");
1373    ok(!$a, "Expect overloaded boolean");
1374}
1375
1376{
1377    package Flrbbbbb;
1378    use overload
1379	bool	 => sub { shift->{truth} eq 'yes' },
1380	'0+'	 => sub { shift->{truth} eq 'yes' ? '1' : '0' },
1381	'!'	 => sub { shift->{truth} eq 'no' },
1382	fallback => 1;
1383
1384    sub new { my $class = shift; bless { truth => shift }, $class }
1385
1386    package main;
1387
1388    my $yes = Flrbbbbb->new('yes');
1389    my $x;
1390    $x = 1 if $yes;			is($x, 1);
1391    $x = 2 unless $yes;			is($x, 1);
1392    $x = 3 if !$yes;			is($x, 1);
1393    $x = 4 unless !$yes;		is($x, 4);
1394
1395    my $no = Flrbbbbb->new('no');
1396    $x = 0;
1397    $x = 1 if $no;			is($x, 0);
1398    $x = 2 unless $no;			is($x, 2);
1399    $x = 3 if !$no;			is($x, 3);
1400    $x = 4 unless !$no;			is($x, 3);
1401
1402    $x = 0;
1403    $x = 1 if !$no && $yes;		is($x, 1);
1404    $x = 2 unless !$no && $yes;		is($x, 1);
1405    $x = 3 if $no || !$yes;		is($x, 1);
1406    $x = 4 unless $no || !$yes;		is($x, 4);
1407
1408    $x = 0;
1409    $x = 1 if !$no || !$yes;		is($x, 1);
1410    $x = 2 unless !$no || !$yes;	is($x, 1);
1411    $x = 3 if !$no && !$yes;		is($x, 1);
1412    $x = 4 unless !$no && !$yes;	is($x, 4);
1413}
1414
1415{
1416    no warnings 'experimental::builtin';
1417    use builtin 'weaken';
1418
1419    package Shklitza;
1420    use overload '""' => sub {"CLiK KLAK"};
1421
1422    package Ksshfwoom;
1423
1424    package main;
1425
1426    my ($obj, $ref);
1427    $obj = bless do {my $a; \$a}, 'Shklitza';
1428    $ref = $obj;
1429
1430    is ("$obj", "CLiK KLAK");
1431    is ("$ref", "CLiK KLAK");
1432
1433    weaken $ref;
1434    is ("$ref", "CLiK KLAK");
1435
1436    bless $obj, 'Ksshfwoom';
1437
1438    like ($obj, qr/^Ksshfwoom=/);
1439    like ($ref, qr/^Ksshfwoom=/);
1440
1441    undef $obj;
1442    is ($ref, undef);
1443}
1444
1445{
1446    package bit;
1447    # bit operations have overloadable assignment variants too
1448
1449    sub new { bless \$_[1], $_[0] }
1450
1451    use overload
1452          "&=" => sub { bit->new($_[0]->val . ' & ' . $_[1]->val) },
1453          "^=" => sub { bit->new($_[0]->val . ' ^ ' . $_[1]->val) },
1454          "|"  => sub { bit->new($_[0]->val . ' | ' . $_[1]->val) }, # |= by fallback
1455          ;
1456
1457    sub val { ${$_[0]} }
1458
1459    package main;
1460
1461    my $a = bit->new(my $va = 'a');
1462    my $b = bit->new(my $vb = 'b');
1463
1464    $a &= $b;
1465    is($a->val, 'a & b', "overloaded &= works");
1466
1467    my $c = bit->new(my $vc = 'c');
1468
1469    $b ^= $c;
1470    is($b->val, 'b ^ c', "overloaded ^= works");
1471
1472    my $d = bit->new(my $vd = 'd');
1473
1474    $c |= $d;
1475    is($c->val, 'c | d', "overloaded |= (by fallback) works");
1476}
1477
1478{
1479    # comparison operators with nomethod (bug 41546)
1480    my $warning = "";
1481    my $method;
1482
1483    package nomethod_false;
1484    use overload nomethod => sub { $method = 'nomethod'; 0 };
1485
1486    package nomethod_true;
1487    use overload nomethod => sub { $method= 'nomethod'; 'true' };
1488
1489    package main;
1490    local $^W = 1;
1491    local $SIG{__WARN__} = sub { $warning = $_[0] };
1492
1493    my $f = bless [], 'nomethod_false';
1494    ($warning, $method) = ("", "");
1495    is($f eq 'whatever', 0, 'nomethod makes eq return 0');
1496    is($method, 'nomethod');
1497
1498    my $t = bless [], 'nomethod_true';
1499    ($warning, $method) = ("", "");
1500    is($t eq 'whatever', 'true', 'nomethod makes eq return "true"');
1501    is($method, 'nomethod');
1502    is($warning, "", 'nomethod eq need not return number');
1503
1504    eval q{
1505        package nomethod_false;
1506        use overload cmp => sub { $method = 'cmp'; 0 };
1507    };
1508    $f = bless [], 'nomethod_false';
1509    ($warning, $method) = ("", "");
1510    ok($f eq 'whatever', 'eq falls back to cmp (nomethod not called)');
1511    is($method, 'cmp');
1512
1513    eval q{
1514        package nomethod_true;
1515        use overload cmp => sub { $method = 'cmp'; 'true' };
1516    };
1517    $t = bless [], 'nomethod_true';
1518    ($warning, $method) = ("", "");
1519    ok($t eq 'whatever', 'eq falls back to cmp (nomethod not called)');
1520    is($method, 'cmp');
1521    like($warning, qr/isn't numeric/, 'cmp should return number');
1522
1523}
1524
1525{
1526    # nomethod called for '!' after attempted fallback
1527    my $nomethod_called = 0;
1528
1529    package nomethod_not;
1530    use overload nomethod => sub { $nomethod_called = 'yes'; };
1531
1532    package main;
1533    my $o = bless [], 'nomethod_not';
1534    my $res = ! $o;
1535
1536    is($nomethod_called, 'yes', "nomethod() is called for '!'");
1537    is($res, 'yes', "nomethod(..., '!') return value propagates");
1538}
1539
1540{
1541    # Subtle bug pre 5.10, as a side effect of the overloading flag being
1542    # stored on the reference rather than the referent. Despite the fact that
1543    # objects can only be accessed via references (even internally), the
1544    # referent actually knows that it's blessed, not the references. So taking
1545    # a new, unrelated, reference to it gives an object. However, the
1546    # overloading-or-not flag was on the reference prior to 5.10, and taking
1547    # a new reference didn't (use to) copy it.
1548
1549    package kayo;
1550
1551    use overload '""' => sub {${$_[0]}};
1552
1553    sub Pie {
1554	return "$_[0], $_[1]";
1555    }
1556
1557    package main;
1558
1559    my $class = 'kayo';
1560    my $string = 'bam';
1561    my $crunch_eth = bless \$string, $class;
1562
1563    is("$crunch_eth", $string);
1564    is ($crunch_eth->Pie("Meat"), "$string, Meat");
1565
1566    my $wham_eth = \$string;
1567
1568    is("$wham_eth", $string,
1569       'This reference did not have overloading in 5.8.8 and earlier');
1570    is ($crunch_eth->Pie("Apple"), "$string, Apple");
1571
1572    my $class = ref $wham_eth;
1573    $class =~ s/=.*//;
1574
1575    # Bless it back into its own class!
1576    bless $wham_eth, $class;
1577
1578    is("$wham_eth", $string);
1579    is ($crunch_eth->Pie("Blackbird"), "$string, Blackbird");
1580}
1581
1582{
1583    package numify_int;
1584    use overload "0+" => sub { $_[0][0] += 1; 42 };
1585    package numify_self;
1586    use overload "0+" => sub { $_[0][0]++; $_[0] };
1587    package numify_other;
1588    use overload "0+" => sub { $_[0][0]++; $_[0][1] = bless [], 'numify_int' };
1589    package numify_by_fallback;
1590    use overload fallback => 1;
1591
1592    package main;
1593    my $o = bless [], 'numify_int';
1594    is(int($o), 42, 'numifies to integer');
1595    is($o->[0], 1, 'int() numifies only once');
1596
1597    my $aref = [];
1598    my $num_val = int($aref);
1599    my $r = bless $aref, 'numify_self';
1600    is(int($r), $num_val, 'numifies to self');
1601    is($r->[0], 1, 'int() numifies once when returning self');
1602
1603    my $s = bless [], 'numify_other';
1604    is(int($s), 42, 'numifies to numification of other object');
1605    is($s->[0], 1, 'int() numifies once when returning other object');
1606    is($s->[1][0], 1, 'returned object numifies too');
1607
1608    my $m = bless $aref, 'numify_by_fallback';
1609    is(int($m), $num_val, 'numifies to usual reference value');
1610    is(abs($m), $num_val, 'numifies to usual reference value');
1611    is(-$m, -$num_val, 'numifies to usual reference value');
1612    is(0+$m, $num_val, 'numifies to usual reference value');
1613    is($m+0, $num_val, 'numifies to usual reference value');
1614    is($m+$m, 2*$num_val, 'numifies to usual reference value');
1615    is(0-$m, -$num_val, 'numifies to usual reference value');
1616    is(1*$m, $num_val, 'numifies to usual reference value');
1617    is(int($m/1), $num_val, 'numifies to usual reference value');
1618    is($m%100, $num_val%100, 'numifies to usual reference value');
1619    is($m**1, $num_val, 'numifies to usual reference value');
1620
1621    is(abs($aref), $num_val, 'abs() of ref');
1622    is(-$aref, -$num_val, 'negative of ref');
1623    is(0+$aref, $num_val, 'ref addition');
1624    is($aref+0, $num_val, 'ref addition');
1625    is($aref+$aref, 2*$num_val, 'ref addition');
1626    is(0-$aref, -$num_val, 'subtraction of ref');
1627    is(1*$aref, $num_val, 'multiplicaton of ref');
1628    is(int($aref/1), $num_val, 'division of ref');
1629    is($aref%100, $num_val%100, 'modulo of ref');
1630    is($aref**1, $num_val, 'exponentiation of ref');
1631}
1632
1633{
1634    package CopyConstructorFallback;
1635    use overload
1636        '++'        => sub { "$_[0]"; $_[0] },
1637        fallback    => 1;
1638    sub new { bless {} => shift }
1639
1640    package main;
1641
1642    my $o = CopyConstructorFallback->new;
1643    my $x = $o++; # would segfault
1644    my $y = ++$o;
1645    is($x, $o, "copy constructor falls back to assignment (postinc)");
1646    is($y, $o, "copy constructor falls back to assignment (preinc)");
1647}
1648
1649# only scalar 'x' should currently overload
1650
1651{
1652    package REPEAT;
1653
1654    my ($x,$n, $nm);
1655
1656    use overload
1657	'x'        => sub { $x++; 1 },
1658	'0+'       => sub { $n++; 1 },
1659	'nomethod' => sub { $nm++; 1 },
1660	'fallback' => 0,
1661    ;
1662
1663    my $s = bless {};
1664
1665    package main;
1666
1667    my @a;
1668    my $count = 3;
1669
1670    ($x,$n,$nm) = (0,0,0);
1671    @a = ((1,2,$s) x $count);
1672    is("$x-$n-$nm", "0-0-0", 'repeat 1');
1673
1674    ($x,$n,$nm) = (0,0,0);
1675    @a = ((1,$s,3) x $count);
1676    is("$x-$n-$nm", "0-0-0", 'repeat 2');
1677
1678    ($x,$n,$nm) = (0,0,0);
1679    @a = ((1,2,3) x $s);
1680    is("$x-$n-$nm", "0-1-0", 'repeat 3');
1681}
1682
1683
1684
1685# RT #57012: magic items need to have mg_get() called before testing for
1686# overload. Lack of this means that overloaded values returned by eg a
1687# tied array didn't call overload methods.
1688# We test here both a tied array and scalar, since the implementation of
1689# tied  arrays (and hashes) is such that in rvalue context, mg_get is
1690# called prior to executing the op, while it isn't for a tied scalar.
1691# We also check that return values are correctly tainted.
1692# We try against two overload packages; one has all expected methods, the
1693# other uses only fallback methods.
1694
1695{
1696
1697    # @tests holds a list of test cases. Each elem is an array ref with
1698    # the following entries:
1699    #
1700    #  * the value that the overload method should return
1701    #
1702    #  * the expression to be evaled. %s is replaced with the
1703    #       variable being tested ($ta[0], $ts, or $plain)
1704    #
1705    #  * a string listing what functions we expect to be called.
1706    #       Each method appends its name in parentheses, so "(=)(+)" means
1707    #       we expect the copy constructor and then the add method to be
1708    #       called.
1709    #
1710    #  * like above, but what should be called for the fallback-only test
1711    #      (in this case, nomethod() identifies itself as "(NM:*)" where *
1712    #      is the op).  If this value is undef, fallback tests are skipped.
1713    #
1714    #  * An array ref of expected counts of calls to FETCH/STORE.
1715    #      The first three values are:
1716    #         1. the expected number of FETCHs for a tied array
1717    #         2. the expected number of FETCHs for a tied scalar
1718    #         3. the expected number of STOREs
1719    #       If there are a further three elements present, then
1720    #       these represent the expected counts for the fallback
1721    #       version of the tests. If absent, they are assumed to
1722    #       be the same as for the full method test
1723    #
1724    #  * Under the taint version of the tests,  whether we expect
1725    #       the result to be tainted (for example comparison ops
1726    #       like '==' don't return a tainted value, even if their
1727    #       args are.
1728    my @tests;
1729
1730    my %subs;
1731    my $funcs;
1732    my $use_int;
1733
1734    BEGIN {
1735	# A note on what methods to expect to be called, and
1736	# how many times FETCH/STORE is called:
1737	#
1738	# Mutating ops (+=, ++ etc) trigger a copy ('='), since
1739	# the code can't distinguish between something that's been copied:
1740	#    $a = foo->new(0); $b = $a; refcnt($$b) == 2
1741	# and overloaded objects stored in ties which will have extra
1742	# refcounts due to the tied_obj magic and entries on the tmps
1743	# stack when returning from FETCH etc. So we always copy.
1744
1745	# This accounts for a '=', and an extra STORE.
1746	# We also have a FETCH returning the final value from the eval,
1747	# plus a FETCH in the overload subs themselves: ($_[0][0])
1748	# triggers one. However, tied aggregates have a mechanism to prevent
1749	# multiple fetches between STOREs, which means that the tied
1750	# hash skips doing a FETCH during '='.
1751
1752	for (qw(+ - * / % ** << >> & | ^)) {
1753	    my $op = $_;
1754	    $op = '%%' if $op eq '%';
1755	    my $e = "%s $op= 3";
1756	    $subs{"$_="} = $e;
1757	    # ARRAY  FETCH: initial,        sub+=, eval-return,
1758	    # SCALAR FETCH: initial, sub=,  sub+=, eval-return,
1759	    # STORE:        copy, mutator
1760	    push @tests, [ 18, $e, "(=)($_=)", "(=)(NM:$_=)", [ 3, 4, 2 ], 1 ];
1761
1762	    $subs{$_} =
1763		"do { my \$arg = %s; \$_[2] ? (3 $op \$arg) : (\$arg $op 3) }";
1764	    # ARRAY  FETCH: initial
1765	    # SCALAR FETCH: initial eval-return,
1766	    push @tests, [ 18, "%s $op 3", "($_)", "(NM:$_)", [ 1, 2, 0 ], 1 ];
1767	    push @tests, [ 18, "3 $op %s", "($_)", "(NM:$_)", [ 1, 2, 0 ], 1 ];
1768	}
1769
1770	# these use string fallback rather than nomethod
1771	for (qw(x .)) {
1772	    my $op = $_;
1773	    my $e = "%s $op= 3";
1774	    $subs{"$_="} = $e;
1775	    # For normal case:
1776	    #   ARRAY  FETCH: initial,        sub+=, eval-return,
1777	    #   SCALAR FETCH: initial, sub=,  sub+=, eval-return,
1778	    #          STORE: copy, mutator
1779	    # for fallback, we just stringify, so eval-return and copy skipped
1780
1781	    push @tests, [ 18, $e, "(=)($_=)", '("")',
1782			    [ 3, 4, 2,     2, 3, 1 ], 1 ];
1783
1784	    $subs{$_} =
1785		"do { my \$arg = %s; \$_[2] ? (3 $op \$arg) : (\$arg $op 3) }";
1786	    # ARRAY  FETCH: initial
1787	    # SCALAR FETCH: initial eval-return,
1788	    # with fallback, we just stringify, so eval-return skipped,
1789	    #    but an extra FETCH happens in sub"", except for 'x',
1790	    #    which passes a copy of the RV to sub"", avoiding the
1791	    #    second FETCH
1792
1793	    push @tests, [ 18, "%s $op 3", "($_)", '("")',
1794			    [ 1, 2, 0,     1, ($_ eq '.' ? 2 : 1), 0 ], 1 ];
1795	    next if $_ eq 'x'; # repeat only overloads on LHS
1796	    push @tests, [ 18, "3 $op %s", "($_)", '("")',
1797			    [ 1, 2, 0,     1, 2, 0 ], 1 ];
1798	}
1799
1800	for (qw(++ --)) {
1801	    my $pre  = "$_%s";
1802	    my $post = "%s$_";
1803	    $subs{$_} = $pre;
1804	    push @tests,
1805		# ARRAY  FETCH: initial,        sub+=, eval-return,
1806		# SCALAR FETCH: initial, sub=,  sub+=, eval-return,
1807		# STORE:        copy, mutator
1808		[ 18, $pre, "(=)($_)(\"\")", "(=)(NM:$_)(\"\")", [ 3, 4, 2 ], 1 ],
1809		# ARRAY  FETCH: initial,        sub+=
1810		# SCALAR FETCH: initial, sub=,  sub+=
1811		# STORE:        copy, mutator
1812		[ 18, $post, "(=)($_)(\"\")", "(=)(NM:$_)(\"\")", [ 2, 3, 2 ], 1 ];
1813	}
1814
1815	# For the non-mutator ops, we have a initial FETCH,
1816	# an extra FETCH within the sub itself for the scalar option,
1817	# and no STOREs
1818
1819	for (qw(< <= >  >= == != lt le gt ge eq ne)) {
1820	    my $e = "%s $_ 3";
1821	    $subs{$_} = $e;
1822	    push @tests, [ 3, $e, "($_)", "(NM:$_)", [ 1, 2, 0 ], 0 ];
1823	}
1824	for (qw(<=> cmp)) {
1825	    my $e = "%s $_ 3";
1826	    $subs{$_} = $e;
1827	    push @tests, [ 3, $e, "($_)", "(NM:$_)", [ 1, 2, 0 ], 1 ];
1828	}
1829	for (qw(atan2)) {
1830	    my $e = "$_ %s, 3";
1831	    $subs{$_} = $e;
1832	    push @tests, [ 18, $e, "($_)", "(NM:$_)", [ 1, 2, 0 ], 1 ];
1833	}
1834	for (qw(cos sin exp abs log sqrt int ~)) {
1835	    my $e = "$_(%s)";
1836	    $subs{$_} = $e;
1837	    push @tests, [ 1.23, $e, "($_)",
1838		    ($_ eq 'int' ? '(0+)' : "(NM:$_)") , [ 1, 2, 0 ], 1 ];
1839	}
1840	for (qw(!)) {
1841	    my $e = "$_(%s)";
1842	    $subs{$_} = $e;
1843	    push @tests, [ 1.23, $e, "($_)", '(0+)', [ 1, 2, 0 ], 0 ];
1844	}
1845	for (qw(-)) {
1846	    my $e = "$_(%s)";
1847	    $subs{neg} = $e;
1848	    push @tests, [ 18, $e, '(neg)', '(NM:neg)', [ 1, 2, 0 ], 1 ];
1849	}
1850	my $e = '(%s) ? 1 : 0';
1851	$subs{bool} = $e;
1852	push @tests, [ 18, $e, '(bool)', '(0+)', [ 1, 2, 0 ], 0 ];
1853
1854	# note: this is testing unary qr, not binary =~
1855	$subs{qr} = '(qr/%s/)';
1856	push @tests, [ "abc", '"abc" =~ (%s)', '(qr)', '("")', [ 1, 2, 0 ], 0 ];
1857	push @tests, [ chr 256, 'chr(256) =~ (%s)', '(qr)', '("")',
1858	                                                  [ 1, 2, 0 ], 0 ];
1859
1860	$e = '"abc" ~~ (%s)';
1861	$subs{'~~'} = $e;
1862	push @tests, [ "abc", $e, '(~~)', '(NM:~~)', [ 1, 1, 0 ], 0 ];
1863
1864	$subs{'-X'} = 'do { my $f = (%s);'
1865		    . '$_[1] eq "r" ? (-r ($f)) :'
1866		    . '$_[1] eq "e" ? (-e ($f)) :'
1867		    . '$_[1] eq "f" ? (-f ($f)) :'
1868		    . '$_[1] eq "l" ? (-l ($f)) :'
1869		    . '$_[1] eq "t" ? (-t ($f)) :'
1870		    . '$_[1] eq "T" ? (-T ($f)) : 0;}';
1871	# Note - we don't care what these file tests return, as
1872	# long as the tied and untied versions return the same value.
1873	# The flags below are chosen to test all uses of tryAMAGICftest_MG
1874	for (qw(r e f l t T)) {
1875	    push @tests, [ 'TEST', "-$_ (%s)", '(-X)', '("")', [ 1, 2, 0 ], 0 ];
1876	}
1877
1878	$subs{'${}'} = '%s';
1879	push @tests, [ do {my $s=99; \$s}, '${%s}', '(${})', undef, [ 1, 1, 0 ], 0 ];
1880
1881	# we skip testing '@{}' here because too much of this test
1882	# framework involves array dereferences!
1883
1884	$subs{'%{}'} = '%s';
1885	push @tests, [ {qw(a 1 b 2 c 3)}, 'join "", sort keys %%{%s}',
1886			'(%{})', undef, [ 1, 1, 0 ], 0 ];
1887
1888	$subs{'&{}'} = '%s';
1889	push @tests, [ sub {99}, 'do {&{%s} for 1,2}',
1890			    '(&{})(&{})', undef, [ 2, 2, 0 ], 0 ];
1891
1892	our $RT57012A = 88;
1893	our $RT57012B;
1894	$subs{'*{}'} = '%s';
1895	push @tests, [ \*RT57012A, '*RT57012B = *{%s}; our $RT57012B',
1896		'(*{})', undef, [ 1, 1, 0 ], 0 ];
1897
1898	my $iter_text = ("some random text\n" x 100) . $^X;
1899	open my $iter_fh, '<', \$iter_text
1900	    or die "open of \$iter_text gave ($!)\n";
1901	$subs{'<>'} = '<$iter_fh>';
1902	push @tests, [ $iter_fh, '<%s>', '(<>)', undef, [ 1, 1, 0 ], 1 ];
1903	push @tests, [ $iter_fh,
1904		      'local *CORE::GLOBAL::glob = sub {}; eval q|<%s>|',
1905		      '(<>)', undef, [ 1, 1, 0 ], 1 ];
1906
1907	# eval should do tie, overload on its arg before checking taint */
1908	push @tests, [ '1;', 'eval q(eval %s); $@ =~ /Insecure/',
1909		'("")', '("")', [ 1, 1, 0 ], 0 ];
1910
1911
1912	for my $sub (keys %subs) {
1913	    no warnings 'deprecated';
1914	    my $term = $subs{$sub};
1915	    my $t = sprintf $term, '$_[0][0]';
1916	    my $e ="sub { \$funcs .= '($sub)'; my \$r; if (\$use_int) {"
1917		. "use integer; \$r = ($t) } else { \$r = ($t) } \$r }";
1918	    $subs{$sub} = eval $e;
1919	    die "Compiling sub gave error:\n<$e>\n<$@>\n" if $@;
1920	}
1921    }
1922
1923    my $fetches;
1924    my $stores;
1925
1926    package RT57012_OV;
1927
1928    use overload
1929	%subs,
1930	"="   => sub { $funcs .= '(=)';  bless [ $_[0][0] ] },
1931	'0+'  => sub { $funcs .= '(0+)'; 0 + $_[0][0] },
1932	'""'  => sub { $funcs .= '("")'; "$_[0][0]"   },
1933	;
1934
1935    package RT57012_OV_FB; # only contains fallback conversion functions
1936
1937    use overload
1938	"="   => sub { $funcs .= '(=)';  bless [ $_[0][0] ] },
1939	'0+'  => sub { $funcs .= '(0+)'; 0 + $_[0][0] },
1940	'""'  => sub { $funcs .= '("")'; "$_[0][0]"   },
1941	"nomethod" => sub {
1942			$funcs .= "(NM:$_[3])";
1943			my $e = defined($_[1])
1944				? $_[3] eq 'atan2'
1945				    ? $_[2]
1946				       ? "atan2(\$_[1],\$_[0][0])"
1947				       : "atan2(\$_[0][0],\$_[1])"
1948				    : $_[2]
1949					? "\$_[1] $_[3] \$_[0][0]"
1950					: "\$_[0][0] $_[3] \$_[1]"
1951				: $_[3] eq 'neg'
1952				    ? "-\$_[0][0]"
1953				    : "$_[3](\$_[0][0])";
1954			my $r;
1955			no warnings 'deprecated';
1956			if ($use_int) {
1957			    use integer; $r = eval $e;
1958			}
1959			else {
1960			    $r = eval $e;
1961			}
1962			::diag("eval of nomethod <$e> gave <$@>") if $@;
1963			$r;
1964		    }
1965
1966	;
1967
1968    package RT57012_TIE_S;
1969
1970    my $tie_val;
1971    sub TIESCALAR { bless [ bless [ $tie_val ], $_[1] ] }
1972    sub FETCH     { $fetches++; $_[0][0] }
1973    sub STORE     { $stores++;  $_[0][0] = $_[1] }
1974
1975    package RT57012_TIE_A;
1976
1977    sub TIEARRAY  { bless [] }
1978    sub FETCH     { $fetches++; $_[0][0] }
1979    sub STORE     { $stores++;  $_[0][$_[1]] = $_[2] }
1980
1981    package main;
1982
1983    for my $test (@tests) {
1984	my ($val, $sub_term, $exp_funcs, $exp_fb_funcs,
1985	    $exp_counts, $exp_taint) = @$test;
1986
1987	my $tainted_val;
1988	{
1989	    # create tainted version of $val (unless its a ref)
1990	    my $t = substr($^X,0,0);
1991	    my $t0 = $t."0";
1992	    my $val1 = $val; # use a copy to avoid stringifying original
1993	    $tainted_val = ref($val1) ? $val :
1994			($val1 =~ /^[\d\.]+$/) ? $val+$t0 : $val.$t;
1995	}
1996	$tie_val = $tainted_val;
1997
1998	for my $int ('', 'use integer; ') {
1999	    $use_int = ($int ne '');
2000	    my $plain = $tainted_val;
2001	    my $plain_term = $int . sprintf $sub_term, '$plain';
2002	    my $exp = do {no warnings 'deprecated'; eval $plain_term };
2003	    diag("eval of plain_term <$plain_term> gave <$@>") if $@;
2004	    SKIP: {
2005		is_if_taint_supported(tainted($exp), $exp_taint,
2006		    "<$plain_term> taint of expected return");
2007	    }
2008
2009	    for my $ov_pkg (qw(RT57012_OV RT57012_OV_FB)) {
2010		next if $ov_pkg eq 'RT57012_OV_FB'
2011			and  not defined $exp_fb_funcs;
2012		my ($exp_fetch_a, $exp_fetch_s, $exp_store) =
2013		    ($ov_pkg eq 'RT57012_OV' || @$exp_counts < 4)
2014			? @$exp_counts[0,1,2]
2015			: @$exp_counts[3,4,5];
2016
2017		tie my $ts, 'RT57012_TIE_S', $ov_pkg;
2018		tie my @ta, 'RT57012_TIE_A';
2019		$ta[0]    = bless [ $tainted_val ], $ov_pkg;
2020		my $oload = bless [ $tainted_val ], $ov_pkg;
2021
2022		for my $var ('$ta[0]', '$ts', '$oload',
2023			    ($sub_term eq '<%s>' ? '${ts}' : ())
2024		) {
2025
2026		    $funcs = '';
2027		    $fetches = 0;
2028		    $stores = 0;
2029
2030		    my $res_term  = $int . sprintf $sub_term, $var;
2031		    my $desc =  "<$res_term> $ov_pkg" ;
2032		    my $res = do { no warnings 'deprecated'; eval $res_term };
2033		    diag("eval of res_term $desc gave <$@>") if $@;
2034		    # uniquely, the inc/dec ops return the original
2035		    # ref rather than a copy, so stringify it to
2036		    # find out if its tainted
2037		    $res = "$res" if $res_term =~ /\+\+|--/;
2038		    SKIP: {
2039			is_if_taint_supported(tainted($res), $exp_taint,
2040			    "$desc taint of result return");
2041		    }
2042		    is($res, $exp, "$desc return value");
2043		    my $fns =($ov_pkg eq 'RT57012_OV_FB')
2044				? $exp_fb_funcs : $exp_funcs;
2045		    if ($var eq '$oload' && $res_term !~ /oload(\+\+|--)/) {
2046			# non-tied overloading doesn't trigger a copy
2047			# except for post inc/dec
2048			$fns =~ s/^\(=\)//;
2049		    }
2050		    is($funcs, $fns, "$desc methods called");
2051		    next if $var eq '$oload';
2052		    my $exp_fetch = ($var eq '$ts') ?
2053			    $exp_fetch_s : $exp_fetch_a;
2054		    SKIP: {
2055			if ($skip_fetch_count_when_no_taint{$desc} && $no_taint_support) {
2056			    skip("your perl was built without taint support");
2057			}
2058			else {
2059			    is($fetches, $exp_fetch, "$desc FETCH count");
2060			}
2061		    }
2062		    is($stores, $exp_store, "$desc STORE count");
2063
2064		}
2065
2066	    }
2067	}
2068    }
2069}
2070
2071# Test overload from the main package
2072fresh_perl_is
2073 '$^W = 1; use overload q\""\ => sub {"ning"}; print bless []',
2074 'ning',
2075  { switches => ['-wl'], stderr => 1 },
2076 'use overload from the main package'
2077;
2078
2079{
2080    package blessed_methods;
2081    use overload '+' => sub {};
2082    bless overload::Method __PACKAGE__,'+';
2083    eval { overload::Method __PACKAGE__,'+' };
2084    ::is($@, '', 'overload::Method and blessed overload methods');
2085}
2086
2087{
2088    # fallback to 'cmp' and '<=>' with heterogeneous operands
2089    # [perl #71286]
2090    my $not_found = 'no method found';
2091    my $used = 0;
2092    package CmpBase;
2093    sub new {
2094        my $n = $_[1] || 0;
2095        bless \$n, ref $_[0] || $_[0];
2096    }
2097    sub cmp {
2098        $used = \$_[0];
2099        (${$_[0]} <=> ${$_[1]}) * ($_[2] ? -1 : 1);
2100    }
2101
2102    package NCmp;
2103    use parent '-norequire', 'CmpBase';
2104    use overload '<=>' => 'cmp';
2105
2106    package SCmp;
2107    use parent '-norequire', 'CmpBase';
2108    use overload 'cmp' => 'cmp';
2109
2110    package main;
2111    my $n = NCmp->new(5);
2112    my $s = SCmp->new(3);
2113    my $res;
2114
2115    eval { $res = $n > $s; };
2116    $res = $not_found if $@ =~ /$not_found/;
2117    is($res, 1, 'A>B using A<=> when B overloaded, no B<=>');
2118
2119    eval { $res = $s < $n; };
2120    $res = $not_found if $@ =~ /$not_found/;
2121    is($res, 1, 'A<B using B<=> when A overloaded, no A<=>');
2122
2123    eval { $res = $s lt $n; };
2124    $res = $not_found if $@ =~ /$not_found/;
2125    is($res, 1, 'A lt B using A:cmp when B overloaded, no B:cmp');
2126
2127    eval { $res = $n gt $s; };
2128    $res = $not_found if $@ =~ /$not_found/;
2129    is($res, 1, 'A gt B using B:cmp when A overloaded, no A:cmp');
2130
2131    my $o = NCmp->new(9);
2132    $res = $n < $o;
2133    is($used, \$n, 'A < B uses <=> from A in preference to B');
2134
2135    my $t = SCmp->new(7);
2136    $res = $s lt $t;
2137    is($used, \$s, 'A lt B uses cmp from A in preference to B');
2138}
2139
2140{
2141    # Combinatorial testing of 'fallback' and 'nomethod'
2142    # [perl #71286]
2143    package NuMB;
2144    use overload '0+' => sub { ${$_[0]}; },
2145        '""' => 'str';
2146    sub new {
2147        my $self = shift;
2148        my $n = @_ ? shift : 0;
2149        bless my $obj = \$n, ref $self || $self;
2150    }
2151    sub str {
2152        no strict qw/refs/;
2153        my $s = "(${$_[0]} ";
2154        $s .= "nomethod, " if defined ${ref($_[0]).'::(nomethod'};
2155        my $fb = ${ref($_[0]).'::()'};
2156        $s .= "fb=" . (defined $fb ? 0 + $fb : 'undef') . ")";
2157    }
2158    sub nomethod { "${$_[0]}.nomethod"; }
2159
2160    # create classes for tests
2161    package main;
2162    my @falls = (0, 'undef', 1);
2163    my @nomethods = ('', 'nomethod');
2164    my $not_found = 'no method found';
2165    for my $fall (@falls) {
2166        for my $nomethod (@nomethods) {
2167            my $nomethod_decl = $nomethod
2168                ? $nomethod . "=>'nomethod'," : '';
2169            eval qq{
2170                    package NuMB$fall$nomethod;
2171                    use parent '-norequire', qw/NuMB/;
2172                    use overload $nomethod_decl
2173                    fallback => $fall;
2174                };
2175        }
2176    }
2177
2178    # operation and precedence of 'fallback' and 'nomethod'
2179    # for all combinations with 2 overloaded operands
2180    for my $nomethod2 (@nomethods) {
2181        for my $nomethod1 (@nomethods) {
2182            for my $fall2 (@falls) {
2183                my $pack2 = "NuMB$fall2$nomethod2";
2184                for my $fall1 (@falls) {
2185                    my $pack1 = "NuMB$fall1$nomethod1";
2186                    my ($test, $out, $exp);
2187                    eval qq{
2188                            my \$x = $pack1->new(2);
2189                            my \$y = $pack2->new(3);
2190                            \$test = "\$x" . ' * ' . "\$y";
2191                            \$out = \$x * \$y;
2192                        };
2193                    $out = $not_found if $@ =~ /$not_found/;
2194                    $exp = $nomethod1 ? '2.nomethod' :
2195                         $nomethod2 ? '3.nomethod' :
2196                         $fall1 eq '1' && $fall2 eq '1' ? 6
2197                         : $not_found;
2198                    is($out, $exp, "$test --> $exp");
2199                }
2200            }
2201        }
2202    }
2203
2204    # operation of 'fallback' and 'nomethod'
2205    # where the other operand is not overloaded
2206    for my $nomethod (@nomethods) {
2207        for my $fall (@falls) {
2208            my ($test, $out, $exp);
2209            eval qq{
2210                    my \$x = NuMB$fall$nomethod->new(2);
2211                    \$test = "\$x" . ' * 3';
2212                    \$out = \$x * 3;
2213                };
2214            $out = $not_found if $@ =~ /$not_found/;
2215            $exp = $nomethod ? '2.nomethod' :
2216                $fall eq '1' ? 6
2217                : $not_found;
2218            is($out, $exp, "$test --> $exp");
2219
2220            eval qq{
2221                    my \$x = NuMB$fall$nomethod->new(2);
2222                    \$test = '3 * ' . "\$x";
2223                    \$out = 3 * \$x;
2224                };
2225            $out = $not_found if $@ =~ /$not_found/;
2226            is($out, $exp, "$test --> $exp");
2227        }
2228    }
2229}
2230
2231# since 5.6 overloaded <> was leaving an extra arg on the stack!
2232
2233{
2234    package Iter1;
2235    use overload '<>' => sub { 11 };
2236    package main;
2237    my $a = bless [], 'Iter1';
2238    my $x;
2239    my @a = (10, ($x = <$a>), 12);
2240    is ($a[0], 10, 'Iter1: a[0]');
2241    is ($a[1], 11, 'Iter1: a[1]');
2242    is ($a[2], 12, 'Iter1: a[2]');
2243    @a = (10, ($x .= <$a>), 12);
2244    is ($a[0],   10, 'Iter1: a[0] concat');
2245    is ($a[1], 1111, 'Iter1: a[1] concat');
2246    is ($a[2],   12, 'Iter1: a[2] concat');
2247}
2248
2249# Some tests for error messages
2250{
2251    package Justus;
2252    use overload '+' => 'justice';
2253    eval {"".bless[]};
2254    ::like $@, qr/^Can't resolve method "justice" overloading "\+" in p(?x:
2255                  )ackage "Justus" at /,
2256      'Error message when explicitly named overload method does not exist';
2257
2258    package JustUs;
2259    our @ISA = 'JustYou';
2260    package JustYou { use overload '+' => 'injustice'; }
2261    "JustUs"->${\"(+"};
2262    eval {"".bless []};
2263    ::like $@, qr/^Stub found while resolving method "\?{3}" overloadin(?x:
2264                  )g "\+" in package "JustUs" at /,
2265      'Error message when sub stub is encountered';
2266}
2267
2268{
2269    # check that the right number of stringifications
2270    # and the correct un-utf8-ifying happen on regex compile
2271    package utf8_match;
2272    my $c;
2273    use overload '""' => sub { $c++; $_[0][0] ? "^\x{100}\$" : "^A\$"; };
2274    my $o = bless [0], 'utf8_match';
2275
2276    $o->[0] = 0;
2277    $c = 0;
2278    ::ok("A" =~  "^A\$",	"regex stringify utf8=0 ol=0 bytes=0");
2279    ::ok("A" =~ $o,		"regex stringify utf8=0 ol=1 bytes=0");
2280    ::is($c, 1,			"regex stringify utf8=0 ol=1 bytes=0 count");
2281
2282    $o->[0] = 1;
2283    $c = 0;
2284    ::ok("\x{100}" =~ "^\x{100}\$",
2285				"regex stringify utf8=1 ol=0 bytes=0");
2286    ::ok("\x{100}" =~ $o,	"regex stringify utf8=1 ol=1 bytes=0");
2287    ::is($c, 1,			"regex stringify utf8=1 ol=1 bytes=0 count");
2288
2289    use bytes;
2290
2291    $o->[0] = 0;
2292    $c = 0;
2293    ::ok("A" =~  "^A\$",	"regex stringify utf8=0 ol=0 bytes=1");
2294    ::ok("A" =~ $o,		"regex stringify utf8=0 ol=1 bytes=1");
2295    ::is($c, 1,			"regex stringify utf8=0 ol=1 bytes=1 count");
2296
2297    $o->[0] = 1;
2298    $c = 0;
2299    ::ok(main::byte_utf8a_to_utf8n("\xc4\x80") =~ "^\x{100}\$",
2300				"regex stringify utf8=1 ol=0 bytes=1");
2301    ::ok(main::byte_utf8a_to_utf8n("\xc4\x80") =~ $o,	"regex stringify utf8=1 ol=1 bytes=1");
2302    ::is($c, 1,			"regex stringify utf8=1 ol=1 bytes=1 count");
2303
2304
2305}
2306
2307# [perl #40333]
2308# overload::Overloaded should not use a ->can designed for autoloading.
2309# This example attempts to be as realistic as possible.  The o class has a
2310# default singleton object, but can have instances, too.  The proxy class
2311# represents proxies for o objects, but class methods delegate to the
2312# singleton.
2313# overload::Overloaded used to return incorrect results for proxy objects.
2314package proxy {
2315    sub new { bless [$_[1]], $_[0] }
2316    sub AUTOLOAD {
2317       our $AUTOLOAD =~ s/.*:://;
2318       &_self->$AUTOLOAD;
2319    }
2320    sub can      { SUPER::can{@_} || &_self->can($_[1]) }
2321    sub _self { ref $_[0] ? $_[0][0] : $o::singleton }
2322}
2323package o     { use overload '""' => sub { 'keck' };
2324                sub new { bless[], $_[0] }
2325                our $singleton = o->new; }
2326ok !overload::Overloaded(new proxy new o),
2327 'overload::Overloaded does not incorrectly return true for proxy classes';
2328
2329# Another test, based on the type of explosive test class for which
2330# perl #40333 was filed.
2331{
2332    package broken_can;
2333    sub can {}
2334    use overload '""' => sub {"Ahoy!"};
2335
2336    package main;
2337    my $obj = bless [], 'broken_can';
2338    ok(overload::Overloaded($obj));
2339}
2340
2341sub eleventative::cos { 'eleven' }
2342sub twelvetative::abs { 'twelve' }
2343sub thirteentative::abs { 'thirteen' }
2344sub fourteentative::abs { 'fourteen' }
2345@eleventative::ISA = twelvetative::;
2346{
2347    my $o = bless [], 'eleventative';
2348    eval 'package eleventative; use overload map +($_)x2, cos=>abs=>';
2349    is cos $o, 'eleven', 'overloading applies to object blessed before';
2350    bless [], 'eleventative';
2351    is cos $o, 'eleven',
2352      'ovrld applies to previously-blessed obj after other obj is blessed';
2353    $o = bless [], 'eleventative';
2354    *eleventative::cos = sub { 'ten' };
2355    is cos $o, 'ten', 'method changes affect overloading';
2356    @eleventative::ISA = thirteentative::;
2357    is abs $o, 'thirteen', 'isa changes affect overloading';
2358    bless $o, 'fourteentative';
2359    @fourteentative::ISA = 'eleventative';
2360    is abs $o, 'fourteen', 'isa changes can turn overloading on';
2361}
2362
2363# no overload "fallback";
2364{ package phake;
2365  use overload fallback => 1, '""' => sub { 'arakas' };
2366  no overload 'fallback';
2367}
2368$a = bless [], 'phake';
2369is "$a", "arakas",
2370    'no overload "fallback" does not stop overload from working';
2371ok !eval { () = $a eq 'mpizeli'; 1 },
2372    'no overload "fallback" resets fallback to undef on overloaded class';
2373{ package ent; use overload fallback => 0, abs => sub{};
2374  our@ISA = 'huorn';
2375  package huorn;
2376  use overload fallback => 1;
2377  package ent;
2378  no overload "fallback"; # disable previous declaration
2379}
2380$a = bless [], ent::;
2381is eval {"$a"}, overload::StrVal($a),
2382    'no overload undoes fallback declaration completetly'
2383 or diag $@;
2384
2385# inherited fallback
2386{
2387 package pervyy;
2388 our @ISA = 'vtoryy';
2389 use overload "abs" =>=> sub {};
2390 package vtoryy;
2391 use overload fallback => 1, 'sin' =>=> sub{}
2392}
2393$a = bless [], pervyy::;
2394is eval {"$a"}, overload::StrVal($a),
2395 'fallback is inherited by classes that have their own overloading'
2396 or diag $@;
2397
2398# package separators in method names
2399{
2400 package mane;
2401 use overload q\""\ => "bear::strength";
2402 use overload bool  => "bear'bouillon";
2403}
2404@bear::ISA = 'food';
2405sub food::strength { 'twine' }
2406sub food::bouillon { 0 }
2407$a = bless[], mane::;
2408is eval { "$a" }, 'twine', ':: in method name' or diag $@;
2409is eval { !$a  },   1,      "' in method name" or diag $@;
2410
2411# [perl #113050] Half of CPAN assumes fallback is under "()"
2412{
2413  package dodo;
2414  use overload '+' => sub {};
2415  no strict;
2416  *{"dodo::()"} = sub{};
2417  ${"dodo::()"} = 1;
2418}
2419$a = bless [],'dodo';
2420is eval {"$a"}, overload::StrVal($a), 'fallback is stored under "()"';
2421
2422# [perl #47119]
2423{
2424    my $context;
2425
2426    {
2427        package Splitter;
2428        use overload '<>' => \&chars;
2429
2430        sub new {
2431            my $class = shift;
2432            my ($string) = @_;
2433            bless \$string, $class;
2434        }
2435
2436        sub chars {
2437            my $self = shift;
2438            my @chars = split //, $$self;
2439            $context = wantarray;
2440            return @chars;
2441        }
2442    }
2443
2444    my $obj = Splitter->new('bar');
2445
2446    $context = 42; # not 1, '', or undef
2447
2448    my @foo = <$obj>;
2449    is($context, 1, "list context (readline list)");
2450    is(scalar(@foo), 3, "correct result (readline list)");
2451    is($foo[0], 'b', "correct result (readline list)");
2452    is($foo[1], 'a', "correct result (readline list)");
2453    is($foo[2], 'r', "correct result (readline list)");
2454
2455    $context = 42;
2456
2457    my $foo = <$obj>;
2458    ok(defined($context), "scalar context (readline scalar)");
2459    is($context, '', "scalar context (readline scalar)");
2460    is($foo, 3, "correct result (readline scalar)");
2461
2462    $context = 42;
2463
2464    <$obj>;
2465    ok(!defined($context), "void context (readline void)");
2466
2467    $context = 42;
2468
2469    my @bar = <${obj}>;
2470    is($context, 1, "list context (glob list)");
2471    is(scalar(@bar), 3, "correct result (glob list)");
2472    is($bar[0], 'b', "correct result (glob list)");
2473    is($bar[1], 'a', "correct result (glob list)");
2474    is($bar[2], 'r', "correct result (glob list)");
2475
2476    $context = 42;
2477
2478    my $bar = <${obj}>;
2479    ok(defined($context), "scalar context (glob scalar)");
2480    is($context, '', "scalar context (glob scalar)");
2481    is($bar, 3, "correct result (glob scalar)");
2482
2483    $context = 42;
2484
2485    <${obj}>;
2486    ok(!defined($context), "void context (glob void)");
2487}
2488{
2489    my $context;
2490
2491    {
2492        package StringWithContext;
2493        use overload '""' => \&stringify;
2494
2495        sub new {
2496            my $class = shift;
2497            my ($string) = @_;
2498            bless \$string, $class;
2499        }
2500
2501        sub stringify {
2502            my $self = shift;
2503            $context = wantarray;
2504            return $$self;
2505        }
2506    }
2507
2508    my $obj = StringWithContext->new('bar');
2509
2510    $context = 42;
2511
2512    my @foo = "".$obj;
2513    ok(defined($context), "scalar context (stringify list)");
2514    is($context, '', "scalar context (stringify list)");
2515    is(scalar(@foo), 1, "correct result (stringify list)");
2516    is($foo[0], 'bar', "correct result (stringify list)");
2517
2518    $context = 42;
2519
2520    my $foo = "".$obj;
2521    ok(defined($context), "scalar context (stringify scalar)");
2522    is($context, '', "scalar context (stringify scalar)");
2523    is($foo, 'bar', "correct result (stringify scalar)");
2524
2525    $context = 42;
2526
2527    "".$obj;
2528
2529    is($context, '', "scalar context (stringify void)");
2530}
2531{
2532    my ($context, $swap);
2533
2534    {
2535        package AddWithContext;
2536        use overload '+' => \&add;
2537
2538        sub new {
2539            my $class = shift;
2540            my ($num) = @_;
2541            bless \$num, $class;
2542        }
2543
2544        sub add {
2545            my $self = shift;
2546            my ($other, $swapped) = @_;
2547            $context = wantarray;
2548            $swap = $swapped;
2549            return ref($self)->new($$self + $other);
2550        }
2551
2552        sub val { ${ $_[0] } }
2553    }
2554
2555    my $obj = AddWithContext->new(6);
2556
2557    $context = $swap = 42;
2558
2559    my @foo = $obj + 7;
2560    ok(defined($context), "scalar context (add list)");
2561    is($context, '', "scalar context (add list)");
2562    ok(defined($swap), "not swapped (add list)");
2563    is($swap, '', "not swapped (add list)");
2564    is(scalar(@foo), 1, "correct result (add list)");
2565    is($foo[0]->val, 13, "correct result (add list)");
2566
2567    $context = $swap = 42;
2568
2569    @foo = 7 + $obj;
2570    ok(defined($context), "scalar context (add list swap)");
2571    is($context, '', "scalar context (add list swap)");
2572    ok(defined($swap), "swapped (add list swap)");
2573    is($swap, 1, "swapped (add list swap)");
2574    is(scalar(@foo), 1, "correct result (add list swap)");
2575    is($foo[0]->val, 13, "correct result (add list swap)");
2576
2577    $context = $swap = 42;
2578
2579    my $foo = $obj + 7;
2580    ok(defined($context), "scalar context (add scalar)");
2581    is($context, '', "scalar context (add scalar)");
2582    ok(defined($swap), "not swapped (add scalar)");
2583    is($swap, '', "not swapped (add scalar)");
2584    is($foo->val, 13, "correct result (add scalar)");
2585
2586    $context = $swap = 42;
2587
2588    my $foo = 7 + $obj;
2589    ok(defined($context), "scalar context (add scalar swap)");
2590    is($context, '', "scalar context (add scalar swap)");
2591    ok(defined($swap), "swapped (add scalar swap)");
2592    is($swap, 1, "swapped (add scalar swap)");
2593    is($foo->val, 13, "correct result (add scalar swap)");
2594
2595    $context = $swap = 42;
2596
2597    $obj + 7;
2598
2599    ok(!defined($context), "void context (add void)");
2600    ok(defined($swap), "not swapped (add void)");
2601    is($swap, '', "not swapped (add void)");
2602
2603    $context = $swap = 42;
2604
2605    7 + $obj;
2606
2607    ok(!defined($context), "void context (add void swap)");
2608    ok(defined($swap), "swapped (add void swap)");
2609    is($swap, 1, "swapped (add void swap)");
2610
2611    $obj = AddWithContext->new(6);
2612
2613    $context = $swap = 42;
2614
2615    my @foo = $obj += 7;
2616    ok(defined($context), "scalar context (add assign list)");
2617    is($context, '', "scalar context (add assign list)");
2618    ok(!defined($swap), "not swapped and autogenerated (add assign list)");
2619    is(scalar(@foo), 1, "correct result (add assign list)");
2620    is($foo[0]->val, 13, "correct result (add assign list)");
2621    is($obj->val, 13, "correct result (add assign list)");
2622
2623    $obj = AddWithContext->new(6);
2624
2625    $context = $swap = 42;
2626
2627    my $foo = $obj += 7;
2628    ok(defined($context), "scalar context (add assign scalar)");
2629    is($context, '', "scalar context (add assign scalar)");
2630    ok(!defined($swap), "not swapped and autogenerated (add assign scalar)");
2631    is($foo->val, 13, "correct result (add assign scalar)");
2632    is($obj->val, 13, "correct result (add assign scalar)");
2633
2634    $obj = AddWithContext->new(6);
2635
2636    $context = $swap = 42;
2637
2638    $obj += 7;
2639
2640    ok(defined($context), "scalar context (add assign void)");
2641    is($context, '', "scalar context (add assign void)");
2642    ok(!defined($swap), "not swapped and autogenerated (add assign void)");
2643    is($obj->val, 13, "correct result (add assign void)");
2644
2645    $obj = AddWithContext->new(6);
2646
2647    $context = $swap = 42;
2648
2649    my @foo = ++$obj;
2650    ok(defined($context), "scalar context (add incr list)");
2651    is($context, '', "scalar context (add incr list)");
2652    ok(!defined($swap), "not swapped and autogenerated (add incr list)");
2653    is(scalar(@foo), 1, "correct result (add incr list)");
2654    is($foo[0]->val, 7, "correct result (add incr list)");
2655    is($obj->val, 7, "correct result (add incr list)");
2656
2657    $obj = AddWithContext->new(6);
2658
2659    $context = $swap = 42;
2660
2661    my $foo = ++$obj;
2662    ok(defined($context), "scalar context (add incr scalar)");
2663    is($context, '', "scalar context (add incr scalar)");
2664    ok(!defined($swap), "not swapped and autogenerated (add incr scalar)");
2665    is($foo->val, 7, "correct result (add incr scalar)");
2666    is($obj->val, 7, "correct result (add incr scalar)");
2667
2668    $obj = AddWithContext->new(6);
2669
2670    $context = $swap = 42;
2671
2672    ++$obj;
2673
2674    ok(defined($context), "scalar context (add incr void)");
2675    is($context, '', "scalar context (add incr void)");
2676    ok(!defined($swap), "not swapped and autogenerated (add incr void)");
2677    is($obj->val, 7, "correct result (add incr void)");
2678}
2679
2680# [perl #113010]
2681{
2682    {
2683        package OnlyFallback;
2684        use overload fallback => 0;
2685    }
2686    {
2687        my $obj = bless {}, 'OnlyFallback';
2688        my $died = !eval { "".$obj; 1 };
2689        my $err = $@;
2690        ok($died, "fallback of 0 causes error");
2691        like($err, qr/"\.": no method found/, "correct error");
2692    }
2693
2694    {
2695        package OnlyFallbackUndef;
2696        use overload fallback => undef;
2697    }
2698    {
2699        my $obj = bless {}, 'OnlyFallbackUndef';
2700        my $died = !eval { "".$obj; 1 };
2701        my $err = $@;
2702        ok($died, "fallback of undef causes error");
2703        # this one tries falling back to stringify before dying
2704        like($err, qr/"""": no method found/, "correct error");
2705    }
2706
2707    {
2708        package OnlyFallbackTrue;
2709        use overload fallback => 1;
2710    }
2711    {
2712        my $obj = bless {}, 'OnlyFallbackTrue';
2713        my $val;
2714        my $died = !eval { $val = "".$obj; 1 };
2715        my $err = $@;
2716        ok(!$died, "fallback of 1 doesn't cause error")
2717            || diag("got error of $err");
2718        like($val, qr/^OnlyFallbackTrue=HASH\(/, "stringified correctly");
2719    }
2720}
2721
2722{
2723    # Making Regexp class overloaded: avoid infinite recursion.
2724    # Do this in a separate process since it, well, overloads Regexp!
2725    fresh_perl_is(
2726	<<'EOF',
2727package Regexp;
2728use overload q{""} => sub {$_[0] };
2729package main;
2730my $r1 = qr/1/;
2731my $r2 = qr/ABC$r1/;
2732print $r2,"\n";
2733EOF
2734	'(?^:ABC(?^:1))',
2735	{ stderr => 1 },
2736	'overloaded REGEXP'
2737    );
2738}
2739
2740{
2741    # RT #121362
2742    # splitting the stash HV while rebuilding the overload cache gave
2743    # valgrind errors. This test code triggers such a split. It doesn't
2744    # actually test anything; its just there for valgrind to spot
2745    # problems.
2746
2747    package A_121362;
2748
2749    sub stringify { }
2750    use overload '""' => 'stringify';
2751
2752    package B_121362;
2753    our @ISA = qw(A_121362);
2754
2755    package main;
2756
2757    my $x = bless { }, 'B_121362';
2758
2759    for ('a'..'z') {
2760        delete $B_121362::{stringify}; # delete cache entry
2761        no strict 'refs';
2762        *{"B_121362::$_"}  = sub { };  # increase size of %B_121362
2763        my $y = $x->{value};       # trigger cache add to %B_121362
2764    }
2765    pass("RT 121362");
2766}
2767
2768package refsgalore {
2769    use overload
2770	'${}' => sub { \42  },
2771	'@{}' => sub { [43] },
2772	'%{}' => sub { { 44 => 45 } },
2773	'&{}' => sub { sub { 46 } };
2774}
2775{
2776    use feature 'postderef';
2777    tell myio; # vivifies *myio{IO} at compile time
2778    use constant ioref => bless *myio{IO}, refsgalore::;
2779    is ioref->$*, 42, '(overloaded constant that is not a scalar ref)->$*';
2780    is ioref->[0], 43, '(ovrld constant that is not an array ref)->[0]';
2781    is ioref->{44}, 45, "(ovrld const that is not a hash ref)->{key}";
2782    is ioref->(), 46, '(overloaded constant that is not a sub ref)->()';
2783}
2784
2785package xstack { use overload 'x' => sub { shift . " x " . shift },
2786                              '""'=> sub { "xstack" } }
2787is join(",", 1..3, scalar((bless([], 'xstack')) x 3, 1), 4..6),
2788  "1,2,3,1,4,5,6",
2789  '(...)x... in void cx with x overloaded [perl #121827]';
2790
2791package bitops {
2792    our @o;
2793    use overload do {
2794	my %o;
2795	for my $o (qw(& | ^ ~ &. |. ^. ~. &= |= ^= &.= |.= ^.=)) {
2796	    $o{$o} = sub {
2797		::ok !defined $_[3], "undef (or nonexistent) arg 3 for $o";
2798		push @o, $o, scalar @_, $_[4]//'u';
2799		$_[0]
2800	    }
2801	}
2802	%o, '=' => sub { bless [] };
2803    }
2804}
2805{
2806    use experimental 'bitwise';
2807    my $o = bless [], bitops::;
2808    $_ = $o & 0;
2809    $_ = $o | 0;
2810    $_ = $o ^ 0;
2811    $_ = ~$o;
2812    $_ = $o &. 0;
2813    $_ = $o |. 0;
2814    $_ = $o ^. 0;
2815    $_ = ~.$o;
2816    $o &= 0;
2817    $o |= 0;
2818    $o ^= 0;
2819    $o &.= 0;
2820    $o |.= 0;
2821    $o ^.= 0;
2822    # elems are in triplets: op, length of @_, numeric? (1/u for y/n)
2823    is "@bitops::o", '& 5 1 | 5 1 ^ 5 1 ~ 5 1 &. 3 u |. 3 u ^. 3 u ~. 3 u ' 		   . '&= 5 1 |= 5 1 ^= 5 1 &.= 3 u |.= 3 u ^.= 3 u',
2824       'experimental "bitwise" ops'
2825}
2826package bitops2 {
2827    our @o;
2828    use overload
2829	 nomethod => sub { push @o, $_[3], scalar @_, $_[4]//'u'; $_[0] },
2830	'=' => sub { bless [] };
2831}
2832{
2833    use experimental 'bitwise';
2834    my $o = bless [], bitops2::;
2835    $_ = $o & 0;
2836    $_ = $o | 0;
2837    $_ = $o ^ 0;
2838    $_ = ~$o;
2839    $_ = $o &. 0;
2840    $_ = $o |. 0;
2841    $_ = $o ^. 0;
2842    $_ = ~.$o;
2843    $o &= 0;
2844    $o |= 0;
2845    $o ^= 0;
2846    $o &.= 0;
2847    $o |.= 0;
2848    $o ^.= 0;
2849    # elems are in triplets: op, length of @_, numeric? (1/u for y/n)
2850    is "@bitops2::o", '& 5 1 | 5 1 ^ 5 1 ~ 5 1 &. 4 u |. 4 u ^. 4 u ~. 4 u ' 		    . '&= 5 1 |= 5 1 ^= 5 1 &.= 4 u |.= 4 u ^.= 4 u',
2851       'experimental "bitwise" ops with nomethod'
2852}
2853
2854package length_utf8 {
2855    use overload '""' => sub { "\x{100}" };
2856    my $o = bless [];
2857print length $o, "\n";
2858
2859    ::is length($o), 1, "overloaded utf8 length";
2860    ::is "$o", "\x{100}", "overloaded utf8 value";
2861}
2862
2863
2864{ # undefining the overload stash -- KEEP THIS TEST LAST
2865    package ant;
2866    use overload '+' => 'onion';
2867    $_ = \&overload::nil;
2868    undef %overload::;
2869    ()=0+bless[];
2870    ::ok(1, 'no crash when undefining %overload::');
2871}
2872
2873
2874# test various aspects of string concat overloading, especially where
2875# multiple concats etc are optimised into a single multiconcat op
2876
2877package Concat {
2878
2879    my $id;
2880
2881    # append a brief description of @_ to $id
2882    sub id {
2883        my @a = map ref $_      ?  "[" . $_->[0] . "]" :
2884                    !defined $_ ? "u"                  :
2885                    $_,
2886                @_;
2887        $id .= '(' . join (',', @a) . ')';
2888    }
2889
2890    use overload
2891        '.'  => sub {
2892                    id('.', @_);
2893                    my ($l, $r, $rev) = @_;
2894                    ($l, $r) = map ref $_ ? $_->[0] : $_, $l, $r;
2895                    ($l,$r) = ($r, $l) if $rev;
2896                    bless [ $l . $r ];
2897                },
2898
2899        '.=' => sub {
2900                    id('.=', @_);
2901                    my ($l, $r, $rev) = @_;
2902                    my ($ll, $rr) = map ref $_ ? $_->[0] : $_, $l, $r;
2903                    die "Unexpected reverse in .=" if $rev;
2904                    $l->[0] .= ref $r ? $r->[0] : $r;
2905                    $l;
2906                },
2907
2908        '=' => sub {
2909                    id('=', @_);
2910                    bless [ $_[0][0] ];
2911                },
2912
2913        '""' => sub {
2914                    id('""', @_);
2915                    $_[0][0];
2916                },
2917    ;
2918
2919    my $a = 'a';
2920    my $b = 'b';
2921    my $c = 'c';
2922    my $A = bless [ 'A' ];
2923    my $B = bless [ 'B' ];
2924    my $C = bless [ 'C' ];
2925
2926    my ($r, $R);
2927
2928
2929    # like cc, but with $is_ref set to 1
2930    sub c {
2931        my ($expr, $expect, $exp_id) = @_;
2932        cc($expr, $expect, 1, $exp_id);
2933    }
2934
2935    # eval $expr, and see if it returns $expect, and whether
2936    # the returned value is a ref ($is_ref). Finally, check that
2937    # $id, which has accumulated info from all overload method calls,
2938    # matches $exp_id.
2939
2940    sub cc {
2941        my ($expr, $expect, $is_ref, $exp_id) = @_;
2942
2943        $id = '';
2944        $r = 'r';
2945        $R = bless ['R'];
2946
2947        my $got = eval $expr;
2948        die "eval failed: $@" if $@;
2949        ::is "$got", $expect,   "expect: $expr";
2950        ::is $id, $exp_id,      "id:     $expr";
2951        ::is ref($got), ($is_ref ? 'Concat' : ''), "is_ref: $expr";
2952    }
2953
2954    # single concats
2955
2956    c '$r=$A.$b',       'Ab',   '(.,[A],b,)("",[Ab],u,)';
2957    c '$r=$a.$B',       'aB',   '(.,[B],a,1)("",[aB],u,)';
2958    c '$r=$A.$B',       'AB',   '(.,[A],[B],)("",[AB],u,)';
2959    c '$R.=$a',         'Ra',   '(.=,[R],a,u)("",[Ra],u,)';
2960    c '$R.=$A',         'RA',   '(.=,[R],[A],u)("",[RA],u,)';
2961
2962   # two concats
2963
2964    c '$r=$A.$b.$c',    'Abc',   '(.,[A],b,)(.=,[Ab],c,u)("",[Abc],u,)';
2965    c '$r=$A.($b.$c)',  'Abc',   '(.,[A],bc,)("",[Abc],u,)';
2966    c '$r=$a.$B.$c',    'aBc',   '(.,[B],a,1)(.=,[aB],c,u)("",[aBc],u,)';
2967    c '$r=$a.($B.$c)',  'aBc',   '(.,[B],c,)(.,[Bc],a,1)("",[aBc],u,)';
2968    c '$r=$a.$b.$C',    'abC',   '(.,[C],ab,1)("",[abC],u,)';
2969    c '$r=$a.($b.$C)',  'abC',   '(.,[C],b,1)(.,[bC],a,1)("",[abC],u,)';
2970
2971   # two concats plus mutator
2972
2973    c '$r.=$A.$b.$c',   'rAbc',  '(.,[A],b,)(.=,[Ab],c,u)(.,[Abc],r,1)'
2974                                .'("",[rAbc],u,)';
2975    c '$r.=$A.($b.$c)', 'rAbc',  '(.,[A],bc,)(.,[Abc],r,1)("",[rAbc],u,)';
2976    c '$r.=$a.$B.$c',   'raBc',  '(.,[B],a,1)(.=,[aB],c,u)(.,[aBc],r,1)'
2977                                .'("",[raBc],u,)';
2978    c '$r.=$a.($B.$c)', 'raBc',  '(.,[B],c,)(.,[Bc],a,1)(.,[aBc],r,1)'
2979                                .'("",[raBc],u,)';
2980    c '$r.=$a.$b.$C',   'rabC',  '(.,[C],ab,1)(.,[abC],r,1)("",[rabC],u,)';
2981    c '$r.=$a.($b.$C)', 'rabC',  '(.,[C],b,1)(.,[bC],a,1)(.,[abC],r,1)'
2982                                .'("",[rabC],u,)';
2983
2984    c '$R.=$A.$b.$c',   'RAbc',  '(.,[A],b,)(.=,[Ab],c,u)(.=,[R],[Abc],u)'
2985                                .'("",[RAbc],u,)';
2986    c '$R.=$A.($b.$c)', 'RAbc',  '(.,[A],bc,)(.=,[R],[Abc],u)("",[RAbc],u,)';
2987    c '$R.=$a.$B.$c',   'RaBc',  '(.,[B],a,1)(.=,[aB],c,u)(.=,[R],[aBc],u)'
2988                                .'("",[RaBc],u,)';
2989    c '$R.=$a.($B.$c)', 'RaBc',  '(.,[B],c,)(.,[Bc],a,1)(.=,[R],[aBc],u)'
2990                                .'("",[RaBc],u,)';
2991    c '$R.=$a.$b.$C',   'RabC',  '(.,[C],ab,1)(.=,[R],[abC],u)("",[RabC],u,)';
2992    c '$R.=$a.($b.$C)', 'RabC',  '(.,[C],b,1)(.,[bC],a,1)(.=,[R],[abC],u)'
2993                                .'("",[RabC],u,)';
2994
2995    # concat over assign
2996
2997    c '($R.=$a).$B.$c', 'RaBc',  '(.=,[R],a,u)(.,[Ra],[B],)(.=,[RaB],c,u)'
2998                                  .'("",[RaBc],u,)';
2999    ::is "$R", "Ra", 'R in concat over assign';
3000
3001
3002    # nested mutators
3003
3004    c '(($R.=$a).=$b).=$c', 'Rabc',  '(.=,[R],a,u)(=,[Ra],u,)(.=,[Ra],b,u)'
3005                                   . '(=,[Rab],u,)(.=,[Rab],c,u)("",[Rabc],u,)';
3006    c '(($R.=$a).=$B).=$c', 'RaBc',  '(.=,[R],a,u)(=,[Ra],u,)(.=,[Ra],[B],u)'
3007                                   . '(=,[RaB],u,)(.=,[RaB],c,u)("",[RaBc],u,)';
3008
3009    # plain SV on both LHS and RHS with RHS object
3010
3011    c '$r=$r.$A.$r',   'rAr',  '(.,[A],r,1)(.=,[rA],r,u)("",[rAr],u,)';
3012    c '$r.=$r.$A.$r',  'rrAr', '(.,[A],r,1)(.=,[rA],r,u)(.,[rAr],r,1)'
3013                              .'("",[rrAr],u,)';
3014
3015    # object on both LHS and RHS
3016
3017    c '$R.=$R',        'RR',    '(.=,[R],[R],u)("",[RR],u,)';
3018    c '$R.=$R.$b.$c',  'RRbc',  '(.,[R],b,)(.=,[Rb],c,u)(.=,[R],[Rbc],u)'
3019                               .'("",[RRbc],u,)';
3020    c '$R.=$a.$R.$c',  'RaRc',  '(.,[R],a,1)(.=,[aR],c,u)(.=,[R],[aRc],u)'
3021                               .'("",[RaRc],u,)';
3022    c '$R.=$a.$b.$R',  'RabR',  '(.,[R],ab,1)(.=,[R],[abR],u)("",[RabR],u,)';
3023
3024
3025    # sprintf shouldn't do concat overloading
3026
3027    cc '$r=sprintf("%s%s%s",$a,$B,$c)',  'aBc',  0, '("",[B],u,)';
3028    cc '$R=sprintf("%s%s%s",$a,$B,$c)',  'aBc',  0, '("",[B],u,)';
3029    cc '$r.=sprintf("%s%s%s",$a,$B,$c)', 'raBc', 0, '("",[B],u,)';
3030    cc '$R.=sprintf("%s%s%s",$a,$B,$c)', 'RaBc', 1, '("",[B],u,)(.=,[R],aBc,u)'
3031                                                   .'("",[RaBc],u,)';
3032
3033    # multiple constants should individually overload (RT #132385)
3034
3035    c '$r=$A."b"."c"', 'Abc',  '(.,[A],b,)(.=,[Ab],c,u)("",[Abc],u,)';
3036
3037    # ... except for this
3038    c '$R.="a"."b"',   'Rab',  '(.=,[R],ab,u)("",[Rab],u,)';
3039}
3040
3041# RT #132385
3042# The first arg of a reversed concat shouldn't be stringified:
3043#      $left . $right
3044#  where $right is overloaded, should invoke
3045#      concat($right, $left, 1)
3046#  rather than
3047#      concat($right, "$left", 1)
3048# There's a similar issue with
3049#      $left .= $right
3050# when left is overloaded
3051
3052package RT132385 {
3053
3054    use constant C => [ "constref" ];
3055
3056    use overload '.' => sub {
3057                            my ($l, $r, $rev) = @_;
3058                            ($l,$r) = ($r,$l) if $rev;
3059                            $l = ref $l ? $l->[0] : "$l";
3060                            $r = ref $r ? $r->[0] : "$r";
3061                            "$l-$r";
3062                        }
3063    ;
3064
3065    my $r1 = [ "ref1" ];
3066    my $r2 = [ "ref2" ];
3067    my $s1 =   "str1";
3068
3069    my $o = bless [ "obj" ];
3070
3071    # try variations that will call either pp_concat or pp_multiconcat,
3072    # with the ref as the first or a later arg
3073
3074    ::is($r1.$o,        "ref1-obj",             "RT #132385 r1.o");
3075    ::is($r1.$o.$s1 ,   "ref1-objstr1",         "RT #132385 r1.o.s1");
3076    ::is("const".$o.$s1 ,"const-objstr1",       "RT #132385 const.o.s1");
3077    ::is(C.$o.$s1       ,"constref-objstr1",    "RT #132385 C.o.s1");
3078
3079    ::like($r1.$r2.$o,   qr/^ARRAY\(0x\w+\)ARRAY\(0x\w+\)-obj/,
3080                                                "RT #132385 r1.r2.o");
3081
3082    # ditto with a mutator
3083    ::is($o .= $r1,     "obj-ref1",             "RT #132385 o.=r1");
3084}
3085
3086# the RHS of an overloaded .= should be passed as-is to the overload
3087# method, rather than being stringified or otherwise being processed in
3088# such a way that it triggers an undef warning
3089package RT132783 {
3090    use warnings;
3091    use overload '.=' => sub { return "foo" };
3092    my $w = 0;
3093    local $SIG{__WARN__} = sub { $w++ };
3094    my $undef;
3095    my $ov = bless [];
3096    $ov .= $undef;
3097    ::is($w, 0, "RT #132783 - should be no warnings");
3098}
3099
3100# changing the overloaded object to a plain string within an overload
3101# method should be permanent.
3102package RT132827 {
3103    use overload '""' => sub { $_[0] = "a" };
3104    my $ov = bless [];
3105    my $b = $ov . "b";
3106    ::is(ref \$ov, "SCALAR", "RT #132827");
3107}
3108
3109# RT #132793
3110# An arg like "$b" in $overloaded .= "$b" should be stringified
3111# before being passed to the method
3112
3113package RT132793 {
3114    my $type;
3115    my $str = 0;
3116    use overload
3117        '.=' => sub { $type = ref(\$_[1]); "foo"; },
3118        '""' => sub { $str++;              "bar" };
3119
3120    my $a = bless {};
3121    my $b = bless {};
3122    $a .= "$b";
3123    ::is($type, "SCALAR", "RT #132793 type");
3124    ::is($str,  1,        "RT #132793 stringify count");
3125}
3126
3127# RT #132801
3128# A second RHS-not-stringified bug
3129
3130package RT132801 {
3131    my $type;
3132    my $str    = 0;
3133    my $concat = 0;
3134    use overload
3135        '.'  => sub { $concat++; bless []; },
3136        '""' => sub { $str++;    "bar" };
3137
3138    my $a = "A";
3139    my $b = bless [];
3140    my $c;
3141    $c = "$a-$b";
3142    ::is($concat, 1, "RT #132801 concat count");
3143    ::is($str,    1, "RT #132801 stringify count");
3144}
3145
3146# General testing of optimising away OP_STRINGIFY, and whether
3147# OP_MULTICONCAT emulates existing behaviour.
3148#
3149# It could well be argued that the existing behaviour is buggy, but
3150# for now emulate the old behaviour.
3151#
3152# In more detail:
3153#
3154# Since 5.000, any OP_STRINGIFY immediately following an OP_CONCAT
3155# is optimised away, on the assumption that since concat will always
3156# return a valid string anyway, it doesn't need stringifying.
3157# So in "$x", the stringify is needed, but on "$x$y" it isn't.
3158# This assumption is flawed once overloading has been introduced, since
3159# concat might return an overloaded object which still needs stringifying.
3160# However, this flawed behaviour is apparently needed by at least one
3161# module, and is tested for in opbasic/concat.t: see RT #124160.
3162#
3163# There is also a wart with the OPpTARGET_MY optimisation: specifically,
3164# in $lex = "...", if $lex is a lexical var, then a chain of 2 or more
3165# concats *doesn't* optimise away OP_STRINGIFY:
3166#
3167# $lex = "$x";        # stringifies
3168# $lex = "$x$y";      # doesn't stringify
3169# $lex = "$x$y$z..."; # stringifies
3170
3171package Stringify {
3172    my $count;
3173    use overload
3174        '.'  => sub {
3175                        my ($a, $b, $rev) = @_;
3176                        bless [ $rev ? "$b" . $a->[0] : $a->[0] . "$b" ];
3177            },
3178        '""' => sub {  $count++; $_[0][0] },
3179    ;
3180
3181    for my $test(
3182        [ 1, '$pkg   =  "$ov"' ],
3183        [ 1, '$lex   =  "$ov"' ],
3184        [ 1, 'my $a  =  "$ov"' ],
3185        [ 1, '$pkg  .=  "$ov"' ],
3186        [ 1, '$lex  .=  "$ov"' ],
3187        [ 1, 'my $a .=  "$ov"' ],
3188
3189        [ 0, '$pkg   =  "$ov$x"' ],
3190        [ 0, '$lex   =  "$ov$x"' ],
3191        [ 0, 'my $a  =  "$ov$x"' ],
3192        [ 0, '$pkg  .=  "$ov$x"' ],
3193        [ 0, '$lex  .=  "$ov$x"' ],
3194        [ 0, 'my $a .=  "$ov$x"' ],
3195
3196        [ 0, '$pkg   =  "$ov$x$y"' ],
3197        [ 1, '$lex   =  "$ov$x$y"' ],  # XXX note the anomaly
3198        [ 0, 'my $a  =  "$ov$x$y"' ],
3199        [ 0, '$pkg  .=  "$ov$x$y"' ],
3200        [ 0, '$lex  .=  "$ov$x$y"' ],
3201        [ 0, 'my $a .=  "$ov$x$y"' ],
3202    )
3203    {
3204        my ($stringify, $code) = @$test;
3205        our $pkg = 'P';
3206        my ($ov, $x, $y, $lex) = (bless(['OV']), qw(X Y L));
3207        $count = 0;
3208        eval "$code; 1" or die $@;
3209        ::is $count, $stringify, $code;
3210    }
3211}
3212
3213# RT #133789: in multiconcat with overload, the overloaded ref returned
3214# from the overload method was being assigned to the pad targ, causing
3215# a delay to the freeing of the object
3216
3217package RT33789 {
3218    use overload
3219        '.'  => sub { $_[0] }
3220    ;
3221
3222    my $destroy = 0;
3223    sub DESTROY { $destroy++ }
3224
3225    {
3226        my $o = bless [];
3227        my $result = '1' . ( '2' . ( '3' . ( '4' . ( '5' . $o ) ) ) );
3228    }
3229    ::is($destroy, 1, "RT #133789: delayed destroy");
3230}
3231
3232# GH #21477: with an overloaded object $obj, ($obj ~~ $scalar) wasn't
3233# popping the original args off the stack. So in list context, rather than
3234# returning (Y/N), it was returning ($obj, $scalar, Y/N)
3235
3236
3237package GH21477 {
3238    use overload
3239        '""'  => sub { $_[0][0]; },
3240        '~~'  => sub { $_[0][0] eq $_[1] },
3241        'eq'  => sub { $_[0][0] eq $_[1] },
3242    ;
3243
3244    my $o = bless ['cat'];
3245
3246    # smartmatch is deprecated and will be removed in 5.042
3247    no warnings 'deprecated';
3248
3249    my @result = ($o ~~ 'cat');
3250    ::is(scalar(@result), 1, "GH #21477: return one result");
3251    ::is($result[0], 1, "GH #21477: return true");
3252
3253    @result = ($o ~~ 'dog');
3254    ::is(scalar(@result), 1, "GH #21477: return one result - part 2");
3255    ::is($result[0], "", "GH #21477: return false");
3256}
3257