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For examples/Atom-timer.pl
  Run on Mon Aug 12 14:45:28 2013
Reported on Mon Aug 12 14:46:15 2013

Filename/Users/dde/perl5/perlbrew/perls/5.18.0t/lib/site_perl/5.18.0/darwin-thread-multi-2level/Variable/Magic.pm
StatementsExecuted 30 statements in 1.04ms
Subroutines
Calls P F Exclusive
Time
Inclusive
Time
Subroutine
11120µs30µsVariable::Magic::::wizardVariable::Magic::wizard
21118µs20µsVariable::Magic::::castVariable::Magic::cast (xsub)
11113µs13µsVariable::Magic::::BEGIN@3Variable::Magic::BEGIN@3
11110µs10µsVariable::Magic::::_wizardVariable::Magic::_wizard (xsub)
1119µs12µsVariable::Magic::::BEGIN@6Variable::Magic::BEGIN@6
1118µs18µsVariable::Magic::::BEGIN@5Variable::Magic::BEGIN@5
1117µs64µsVariable::Magic::::BEGIN@636Variable::Magic::BEGIN@636
1117µs257µsVariable::Magic::::BEGIN@210Variable::Magic::BEGIN@210
1113µs3µsVariable::Magic::::BEGIN@19Variable::Magic::BEGIN@19
2111µs1µsVariable::Magic::::getdataVariable::Magic::getdata (xsub)
Call graph for these subroutines as a Graphviz dot language file.
Line State
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Time
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Calls Time
in subs
Code
1package Variable::Magic;
2
3238µs113µs
# spent 13µs within Variable::Magic::BEGIN@3 which was called: # once (13µs+0s) by Module::Runtime::require_module at line 3
use 5.008;
# spent 13µs making 1 call to Variable::Magic::BEGIN@3
4
5219µs227µs
# spent 18µs (8+10) within Variable::Magic::BEGIN@5 which was called: # once (8µs+10µs) by Module::Runtime::require_module at line 5
use strict;
# spent 18µs making 1 call to Variable::Magic::BEGIN@5 # spent 10µs making 1 call to strict::import
6238µs215µs
# spent 12µs (9+3) within Variable::Magic::BEGIN@6 which was called: # once (9µs+3µs) by Module::Runtime::require_module at line 6
use warnings;
# spent 12µs making 1 call to Variable::Magic::BEGIN@6 # spent 3µs making 1 call to warnings::import
7
8=head1 NAME
9
10Variable::Magic - Associate user-defined magic to variables from Perl.
11
12=head1 VERSION
13
14Version 0.52
15
16=cut
17
1810sour $VERSION;
19
# spent 3µs within Variable::Magic::BEGIN@19 which was called: # once (3µs+0s) by Module::Runtime::require_module at line 21
BEGIN {
2013µs $VERSION = '0.52';
211122µs13µs}
# spent 3µs making 1 call to Variable::Magic::BEGIN@19
22
23=head1 SYNOPSIS
24
25 use Variable::Magic qw<wizard cast VMG_OP_INFO_NAME>;
26
27 { # A variable tracer
28 my $wiz = wizard(
29 set => sub { print "now set to ${$_[0]}!\n" },
30 free => sub { print "destroyed!\n" },
31 );
32
33 my $a = 1;
34 cast $a, $wiz;
35 $a = 2; # "now set to 2!"
36 } # "destroyed!"
37
38 { # A hash with a default value
39 my $wiz = wizard(
40 data => sub { $_[1] },
41 fetch => sub { $_[2] = $_[1] unless exists $_[0]->{$_[2]}; () },
42 store => sub { print "key $_[2] stored in $_[-1]\n" },
43 copy_key => 1,
44 op_info => VMG_OP_INFO_NAME,
45 );
46
47 my %h = (_default => 0, apple => 2);
48 cast %h, $wiz, '_default';
49 print $h{banana}, "\n"; # "0" (there is no 'banana' key in %h)
50 $h{pear} = 1; # "key pear stored in helem"
51 }
52
53=head1 DESCRIPTION
54
55Magic is Perl's way of enhancing variables.
56This mechanism lets the user add extra data to any variable and hook syntactical operations (such as access, assignment or destruction) that can be applied to it.
57With this module, you can add your own magic to any variable without having to write a single line of XS.
58
59You'll realize that these magic variables look a lot like tied variables.
60It is not surprising, as tied variables are implemented as a special kind of magic, just like any 'irregular' Perl variable : scalars like C<$!>, C<$(> or C<$^W>, the C<%ENV> and C<%SIG> hashes, the C<@ISA> array, C<vec()> and C<substr()> lvalues, L<threads::shared> variables...
61They all share the same underlying C API, and this module gives you direct access to it.
62
63Still, the magic made available by this module differs from tieing and overloading in several ways :
64
65=over 4
66
67=item *
68
69Magic is not copied on assignment.
70
71You attach it to variables, not values (as for blessed references).
72
73=item *
74
75Magic does not replace the original semantics.
76
77Magic callbacks usually get triggered before the original action takes place, and cannot prevent it from happening.
78This also makes catching individual events easier than with C<tie>, where you have to provide fallbacks methods for all actions by usually inheriting from the correct C<Tie::Std*> class and overriding individual methods in your own class.
79
80=item *
81
82Magic is multivalued.
83
84You can safely apply different kinds of magics to the same variable, and each of them will be invoked successively.
85
86=item *
87
88Magic is type-agnostic.
89
90The same magic can be applied on scalars, arrays, hashes, subs or globs.
91But the same hook (see below for a list) may trigger differently depending on the the type of the variable.
92
93=item *
94
95Magic is invisible at Perl level.
96
97Magical and non-magical variables cannot be distinguished with C<ref>, C<tied> or another trick.
98
99=item *
100
101Magic is notably faster.
102
103Mainly because perl's way of handling magic is lighter by nature, and because there is no need for any method resolution.
104Also, since you don't have to reimplement all the variable semantics, you only pay for what you actually use.
105
106=back
107
108The operations that can be overloaded are :
109
110=over 4
111
112=item *
113
114I<get>
115
116This magic is invoked when the variable is evaluated.
117It is never called for arrays and hashes.
118
119=item *
120
121I<set>
122
123This magic is called each time the value of the variable changes.
124It is called for array subscripts and slices, but never for hashes.
125
126=item *
127
128I<len>
129
130This magic only applies to arrays (though it used to also apply to scalars), and is triggered when the 'size' or the 'length' of the variable has to be known by Perl.
131This is typically the magic involved when an array is evaluated in scalar context, but also on array assignment and loops (C<for>, C<map> or C<grep>).
132The length is returned from the callback as an integer.
133
134Starting from perl 5.12, this magic is no longer called by the C<length> keyword, and starting from perl 5.17.4 it is also no longer called for scalars in any situation, making this magic only meaningful on arrays.
135You can use the constants L</VMG_COMPAT_SCALAR_LENGTH_NOLEN> and L</VMG_COMPAT_SCALAR_NOLEN> to see if this magic is available for scalars or not.
136
137=item *
138
139I<clear>
140
141This magic is invoked when the variable is reset, such as when an array is emptied.
142Please note that this is different from undefining the variable, even though the magic is called when the clearing is a result of the undefine (e.g. for an array, but actually a bug prevent it to work before perl 5.9.5 - see the L<history|/PERL MAGIC HISTORY>).
143
144=item *
145
146I<free>
147
148This magic is called when a variable is destroyed as the result of going out of scope (but not when it is undefined).
149It behaves roughly like Perl object destructors (i.e. C<DESTROY> methods), except that exceptions thrown from inside a I<free> callback will always be propagated to the surrounding code.
150
151=item *
152
153I<copy>
154
155This magic only applies to tied arrays and hashes, and fires when you try to access or change their elements.
156
157=item *
158
159I<dup>
160
161This magic is invoked when the variable is cloned across threads.
162It is currently not available.
163
164=item *
165
166I<local>
167
168When this magic is set on a variable, all subsequent localizations of the variable will trigger the callback.
169It is available on your perl if and only if C<MGf_LOCAL> is true.
170
171=back
172
173The following actions only apply to hashes and are available if and only if L</VMG_UVAR> is true.
174They are referred to as I<uvar> magics.
175
176=over 4
177
178=item *
179
180I<fetch>
181
182This magic is invoked each time an element is fetched from the hash.
183
184=item *
185
186I<store>
187
188This one is called when an element is stored into the hash.
189
190=item *
191
192I<exists>
193
194This magic fires when a key is tested for existence in the hash.
195
196=item *
197
198I<delete>
199
200This magic is triggered when a key is deleted in the hash, regardless of whether the key actually exists in it.
201
202=back
203
204You can refer to the tests to have more insight of where the different magics are invoked.
205
206=head1 FUNCTIONS
207
208=cut
209
210
# spent 257µs (7+250) within Variable::Magic::BEGIN@210 which was called: # once (7µs+250µs) by Module::Runtime::require_module at line 213
BEGIN {
2111200ns require XSLoader;
2121257µs1250µs XSLoader::load(__PACKAGE__, $VERSION);
# spent 250µs making 1 call to XSLoader::load
2131373µs1257µs}
# spent 257µs making 1 call to Variable::Magic::BEGIN@210
214
215=head2 C<wizard>
216
217 wizard(
218 data => sub { ... },
219 get => sub { my ($ref, $data [, $op]) = @_; ... },
220 set => sub { my ($ref, $data [, $op]) = @_; ... },
221 len => sub {
222 my ($ref, $data, $len [, $op]) = @_; ... ; return $newlen
223 },
224 clear => sub { my ($ref, $data [, $op]) = @_; ... },
225 free => sub { my ($ref, $data [, $op]) = @_, ... },
226 copy => sub { my ($ref, $data, $key, $elt [, $op]) = @_; ... },
227 local => sub { my ($ref, $data [, $op]) = @_; ... },
228 fetch => sub { my ($ref, $data, $key [, $op]) = @_; ... },
229 store => sub { my ($ref, $data, $key [, $op]) = @_; ... },
230 exists => sub { my ($ref, $data, $key [, $op]) = @_; ... },
231 delete => sub { my ($ref, $data, $key [, $op]) = @_; ... },
232 copy_key => $bool,
233 op_info => [ 0 | VMG_OP_INFO_NAME | VMG_OP_INFO_OBJECT ],
234 )
235
236This function creates a 'wizard', an opaque object that holds the magic information.
237It takes a list of keys / values as argument, whose keys can be :
238
239=over 4
240
241=item *
242
243C<data>
244
245A code (or string) reference to a private data constructor.
246It is called in scalar context each time the magic is cast onto a variable, with C<$_[0]> being a reference to this variable and C<@_[1 .. @_-1]> being all extra arguments that were passed to L</cast>.
247The scalar returned from this call is then attached to the variable and can be retrieved later with L</getdata>.
248
249=item *
250
251C<get>, C<set>, C<len>, C<clear>, C<free>, C<copy>, C<local>, C<fetch>, C<store>, C<exists> and C<delete>
252
253Code (or string) references to the respective magic callbacks.
254You don't have to specify all of them : the magic corresponding to undefined entries will simply not be hooked.
255
256When those callbacks are executed, C<$_[0]> is a reference to the magic variable and C<$_[1]> is the associated private data (or C<undef> when no private data constructor is supplied with the wizard).
257Other arguments depend on which kind of magic is involved :
258
259=over 8
260
261=item *
262
263I<len>
264
265C<$_[2]> contains the natural, non-magical length of the variable (which can only be a scalar or an array as I<len> magic is only relevant for these types).
266The callback is expected to return the new scalar or array length to use, or C<undef> to default to the normal length.
267
268=item *
269
270I<copy>
271
272C<$_[2]> is a either an alias or a copy of the current key, and C<$_[3]> is an alias to the current element (i.e. the value).
273Because C<$_[2]> might be a copy, it is useless to try to change it or cast magic on it.
274
275=item *
276
277I<fetch>, I<store>, I<exists> and I<delete>
278
279C<$_[2]> is an alias to the current key.
280Note that C<$_[2]> may rightfully be readonly if the key comes from a bareword, and as such it is unsafe to assign to it.
281You can ask for a copy instead by passing C<< copy_key => 1 >> to L</wizard> which, at the price of a small performance hit, allows you to safely assign to C<$_[2]> in order to e.g. redirect the action to another key.
282
283=back
284
285Finally, if C<< op_info => $num >> is also passed to C<wizard>, then one extra element is appended to C<@_>.
286Its nature depends on the value of C<$num> :
287
288=over 8
289
290=item *
291
292C<VMG_OP_INFO_NAME>
293
294C<$_[-1]> is the current op name.
295
296=item *
297
298C<VMG_OP_INFO_OBJECT>
299
300C<$_[-1]> is the C<B::OP> object for the current op.
301
302=back
303
304Both result in a small performance hit, but just getting the name is lighter than getting the op object.
305
306These callbacks are executed in scalar context and are expected to return an integer, which is then passed straight to the perl magic API.
307However, only the return value of the I<len> magic callback currently holds a meaning.
308
309=back
310
311Each callback can be specified as :
312
313=over 4
314
315=item *
316
317a code reference, which will be called as a subroutine.
318
319=item *
320
321a string reference, where the string denotes which subroutine is to be called when magic is triggered.
322If the subroutine name is not fully qualified, then the current package at the time the magic is invoked will be used instead.
323
324=item *
325
326a reference to C<undef>, in which case a no-op magic callback is installed instead of the default one.
327This may especially be helpful for I<local> magic, where an empty callback prevents magic from being copied during localization.
328
329=back
330
331Note that I<free> magic is never called during global destruction, as there is no way to ensure that the wizard object and the callback were not destroyed before the variable.
332
333Here is a simple usage example :
334
335 # A simple scalar tracer
336 my $wiz = wizard(
337 get => sub { print STDERR "got ${$_[0]}\n" },
338 set => sub { print STDERR "set to ${$_[0]}\n" },
339 free => sub { print STDERR "${$_[0]} was deleted\n" },
340 );
341
342=cut
343
344
# spent 30µs (20+11) within Variable::Magic::wizard which was called: # once (20µs+11µs) by Module::Runtime::require_module at line 33 of B/Hooks/EndOfScope/XS.pm
sub wizard {
3451400ns if (@_ % 2) {
346 require Carp;
347 Carp::croak('Wrong number of arguments for wizard()');
348 }
349
35012µs my %opts = @_;
351
35212µs my @keys = qw<op_info data get set len clear free copy dup>;
3531300ns push @keys, 'local' if MGf_LOCAL;
35411µs push @keys, qw<fetch store exists delete copy_key> if VMG_UVAR;
355
35610s my ($wiz, $err);
357 {
3582100ns local $@;
359220µs110µs $wiz = eval { _wizard(map $opts{$_}, @keys) };
# spent 10µs making 1 call to Variable::Magic::_wizard
3601500ns $err = $@;
361 }
3621100ns if ($err) {
363 $err =~ s/\sat\s+.*?\n//;
364 require Carp;
365 Carp::croak($err);
366 }
367
36815µs return $wiz;
369}
370
371=head2 C<cast>
372
373 cast [$@%&*]var, $wiz, @args
374
375This function associates C<$wiz> magic to the supplied variable, without overwriting any other kind of magic.
376It returns true on success or when C<$wiz> magic is already attached, and croaks on error.
377When C<$wiz> provides a data constructor, it is called just before magic is cast onto the variable, and it receives a reference to the target variable in C<$_[0]> and the content of C<@args> in C<@_[1 .. @args]>.
378Otherwise, C<@args> is ignored.
379
380 # Casts $wiz onto $x, passing (\$x, '1') to the data constructor.
381 my $x;
382 cast $x, $wiz, 1;
383
384The C<var> argument can be an array or hash value.
385Magic for these scalars behaves like for any other, except that it is dispelled when the entry is deleted from the container.
386For example, if you want to call C<POSIX::tzset> each time the C<'TZ'> environment variable is changed in C<%ENV>, you can use :
387
388 use POSIX;
389 cast $ENV{TZ}, wizard set => sub { POSIX::tzset(); () };
390
391If you want to handle the possible deletion of the C<'TZ'> entry, you must also specify I<store> magic.
392
393=head2 C<getdata>
394
395 getdata [$@%&*]var, $wiz
396
397This accessor fetches the private data associated with the magic C<$wiz> in the variable.
398It croaks when C<$wiz> does not represent a valid magic object, and returns an empty list if no such magic is attached to the variable or when the wizard has no data constructor.
399
400 # Get the data attached to $wiz in $x, or undef if $wiz
401 # did not attach any.
402 my $data = getdata $x, $wiz;
403
404=head2 C<dispell>
405
406 dispell [$@%&*]variable, $wiz
407
408The exact opposite of L</cast> : it dissociates C<$wiz> magic from the variable.
409This function returns true on success, C<0> when no magic represented by C<$wiz> could be found in the variable, and croaks if the supplied wizard is invalid.
410
411 # Dispell now.
412 die 'no such magic in $x' unless dispell $x, $wiz;
413
414=head1 CONSTANTS
415
416=head2 C<MGf_COPY>
417
418Evaluates to true if and only if the I<copy> magic is available.
419This is the case for perl 5.7.3 and greater, which is ensured by the requirements of this module.
420
421=head2 C<MGf_DUP>
422
423Evaluates to true if and only if the I<dup> magic is available.
424This is the case for perl 5.7.3 and greater, which is ensured by the requirements of this module.
425
426=head2 C<MGf_LOCAL>
427
428Evaluates to true if and only if the I<local> magic is available.
429This is the case for perl 5.9.3 and greater.
430
431=head2 C<VMG_UVAR>
432
433When this constant is true, you can use the I<fetch>, I<store>, I<exists> and I<delete> magics on hashes.
434Initial L</VMG_UVAR> capability was introduced in perl 5.9.5, with a fully functional implementation shipped with perl 5.10.0.
435
436=head2 C<VMG_COMPAT_SCALAR_LENGTH_NOLEN>
437
438True for perls that don't call I<len> magic when taking the C<length> of a magical scalar.
439
440=head2 C<VMG_COMPAT_SCALAR_NOLEN>
441
442True for perls that don't call I<len> magic on scalars.
443Implies L</VMG_COMPAT_SCALAR_LENGTH_NOLEN>.
444
445=head2 C<VMG_COMPAT_ARRAY_PUSH_NOLEN>
446
447True for perls that don't call I<len> magic when you push an element in a magical array.
448Starting from perl 5.11.0, this only refers to pushes in non-void context and hence is false.
449
450=head2 C<VMG_COMPAT_ARRAY_PUSH_NOLEN_VOID>
451
452True for perls that don't call I<len> magic when you push in void context an element in a magical array.
453
454=head2 C<VMG_COMPAT_ARRAY_UNSHIFT_NOLEN_VOID>
455
456True for perls that don't call I<len> magic when you unshift in void context an element in a magical array.
457
458=head2 C<VMG_COMPAT_ARRAY_UNDEF_CLEAR>
459
460True for perls that call I<clear> magic when undefining magical arrays.
461
462=head2 C<VMG_COMPAT_HASH_DELETE_NOUVAR_VOID>
463
464True for perls that don't call I<delete> magic when you delete an element from a hash in void context.
465
466=head2 C<VMG_COMPAT_GLOB_GET>
467
468True for perls that call I<get> magic for operations on globs.
469
470=head2 C<VMG_PERL_PATCHLEVEL>
471
472The perl patchlevel this module was built with, or C<0> for non-debugging perls.
473
474=head2 C<VMG_THREADSAFE>
475
476True if and only if this module could have been built with thread-safety features enabled.
477
478=head2 C<VMG_FORKSAFE>
479
480True if and only if this module could have been built with fork-safety features enabled.
481This is always true except on Windows where it is false for perl 5.10.0 and below.
482
483=head2 C<VMG_OP_INFO_NAME>
484
485Value to pass with C<op_info> to get the current op name in the magic callbacks.
486
487=head2 C<VMG_OP_INFO_OBJECT>
488
489Value to pass with C<op_info> to get a C<B::OP> object representing the current op in the magic callbacks.
490
491=head1 COOKBOOK
492
493=head2 Associate an object to any perl variable
494
495This technique can be useful for passing user data through limited APIs.
496It is similar to using inside-out objects, but without the drawback of having to implement a complex destructor.
497
498 {
499 package Magical::UserData;
500
501 use Variable::Magic qw<wizard cast getdata>;
502
503 my $wiz = wizard data => sub { \$_[1] };
504
505 sub ud (\[$@%*&]) : lvalue {
506 my ($var) = @_;
507 my $data = &getdata($var, $wiz);
508 unless (defined $data) {
509 $data = \(my $slot);
510 &cast($var, $wiz, $slot)
511 or die "Couldn't cast UserData magic onto the variable";
512 }
513 $$data;
514 }
515 }
516
517 {
518 BEGIN { *ud = \&Magical::UserData::ud }
519
520 my $cb;
521 $cb = sub { print 'Hello, ', ud(&$cb), "!\n" };
522
523 ud(&$cb) = 'world';
524 $cb->(); # Hello, world!
525 }
526
527=head2 Recursively cast magic on datastructures
528
529C<cast> can be called from any magical callback, and in particular from C<data>.
530This allows you to recursively cast magic on datastructures :
531
532 my $wiz;
533 $wiz = wizard data => sub {
534 my ($var, $depth) = @_;
535 $depth ||= 0;
536 my $r = ref $var;
537 if ($r eq 'ARRAY') {
538 &cast((ref() ? $_ : \$_), $wiz, $depth + 1) for @$var;
539 } elsif ($r eq 'HASH') {
540 &cast((ref() ? $_ : \$_), $wiz, $depth + 1) for values %$var;
541 }
542 return $depth;
543 },
544 free => sub {
545 my ($var, $depth) = @_;
546 my $r = ref $var;
547 print "free $r at depth $depth\n";
548 ();
549 };
550
551 {
552 my %h = (
553 a => [ 1, 2 ],
554 b => { c => 3 }
555 );
556 cast %h, $wiz;
557 }
558
559When C<%h> goes out of scope, this prints something among the lines of :
560
561 free HASH at depth 0
562 free HASH at depth 1
563 free SCALAR at depth 2
564 free ARRAY at depth 1
565 free SCALAR at depth 3
566 free SCALAR at depth 3
567
568Of course, this example does nothing with the values that are added after the C<cast>.
569
570=head1 PERL MAGIC HISTORY
571
572The places where magic is invoked have changed a bit through perl history.
573Here is a little list of the most recent ones.
574
575=over 4
576
577=item *
578
579B<5.6.x>
580
581I<p14416> : I<copy> and I<dup> magic.
582
583=item *
584
585B<5.8.9>
586
587I<p28160> : Integration of I<p25854> (see below).
588
589I<p32542> : Integration of I<p31473> (see below).
590
591=item *
592
593B<5.9.3>
594
595I<p25854> : I<len> magic is no longer called when pushing an element into a magic array.
596
597I<p26569> : I<local> magic.
598
599=item *
600
601B<5.9.5>
602
603I<p31064> : Meaningful I<uvar> magic.
604
605I<p31473> : I<clear> magic was not invoked when undefining an array.
606The bug is fixed as of this version.
607
608=item *
609
610B<5.10.0>
611
612Since C<PERL_MAGIC_uvar> is uppercased, C<hv_magic_check()> triggers I<copy> magic on hash stores for (non-tied) hashes that also have I<uvar> magic.
613
614=item *
615
616B<5.11.x>
617
618I<p32969> : I<len> magic is no longer invoked when calling C<length> with a magical scalar.
619
620I<p34908> : I<len> magic is no longer called when pushing / unshifting an element into a magical array in void context.
621The C<push> part was already covered by I<p25854>.
622
623I<g9cdcb38b> : I<len> magic is called again when pushing into a magical array in non-void context.
624
625=back
626
627=head1 EXPORT
628
629The functions L</wizard>, L</cast>, L</getdata> and L</dispell> are only exported on request.
630All of them are exported by the tags C<':funcs'> and C<':all'>.
631
632All the constants are also only exported on request, either individually or by the tags C<':consts'> and C<':all'>.
633
634=cut
635
6362131µs2122µs
# spent 64µs (7+57) within Variable::Magic::BEGIN@636 which was called: # once (7µs+57µs) by Module::Runtime::require_module at line 636
use base qw<Exporter>;
# spent 64µs making 1 call to Variable::Magic::BEGIN@636 # spent 58µs making 1 call to base::import
637
6381400nsour @EXPORT = ();
63915µsour %EXPORT_TAGS = (
640 'funcs' => [ qw<wizard cast getdata dispell> ],
641 'consts' => [ qw<
642 MGf_COPY MGf_DUP MGf_LOCAL VMG_UVAR
643 VMG_COMPAT_SCALAR_LENGTH_NOLEN
644 VMG_COMPAT_SCALAR_NOLEN
645 VMG_COMPAT_ARRAY_PUSH_NOLEN VMG_COMPAT_ARRAY_PUSH_NOLEN_VOID
646 VMG_COMPAT_ARRAY_UNSHIFT_NOLEN_VOID
647 VMG_COMPAT_ARRAY_UNDEF_CLEAR
648 VMG_COMPAT_HASH_DELETE_NOUVAR_VOID
649 VMG_COMPAT_GLOB_GET
650 VMG_PERL_PATCHLEVEL
651 VMG_THREADSAFE VMG_FORKSAFE
652 VMG_OP_INFO_NAME VMG_OP_INFO_OBJECT
653 > ],
654);
65516µsour @EXPORT_OK = map { @$_ } values %EXPORT_TAGS;
65615µs$EXPORT_TAGS{'all'} = [ @EXPORT_OK ];
657
658=head1 CAVEATS
659
660In order to hook hash operations with magic, you need at least perl 5.10.0 (see L</VMG_UVAR>).
661
662If you want to store a magic object in the private data slot, you will not be able to recover the magic with L</getdata>, since magic is not copied by assignment.
663You can work around this gotcha by storing a reference to the magic object instead.
664
665If you define a wizard with I<free> magic and cast it on itself, it results in a memory cycle, so this destructor will not be called when the wizard is freed.
666
667=head1 DEPENDENCIES
668
669L<perl> 5.8.
670
671A C compiler.
672This module may happen to build with a C++ compiler as well, but don't rely on it, as no guarantee is made in this regard.
673
674L<Carp> (core since perl 5), L<XSLoader> (since 5.006).
675
676Copy tests need L<Tie::Array> (core since perl 5.005) and L<Tie::Hash> (since 5.002).
677Some uvar tests need L<Hash::Util::FieldHash> (since 5.009004).
678Glob tests need L<Symbol> (since 5.002).
679Threads tests need L<threads> and L<threads::shared> (both since 5.007003).
680
681=head1 SEE ALSO
682
683L<perlguts> and L<perlapi> for internal information about magic.
684
685L<perltie> and L<overload> for other ways of enhancing objects.
686
687=head1 AUTHOR
688
689Vincent Pit, C<< <perl at profvince.com> >>, L<http://www.profvince.com>.
690
691You can contact me by mail or on C<irc.perl.org> (vincent).
692
693=head1 BUGS
694
695Please report any bugs or feature requests to C<bug-variable-magic at rt.cpan.org>, or through the web interface at L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Variable-Magic>.
696I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.
697
698=head1 SUPPORT
699
700You can find documentation for this module with the perldoc command.
701
702 perldoc Variable::Magic
703
704Tests code coverage report is available at L<http://www.profvince.com/perl/cover/Variable-Magic>.
705
706=head1 COPYRIGHT & LICENSE
707
708Copyright 2007,2008,2009,2010,2011,2012 Vincent Pit, all rights reserved.
709
710This program is free software; you can redistribute it and/or modify it
711under the same terms as Perl itself.
712
713=cut
714
71517µs1; # End of Variable::Magic
 
# spent 10µs within Variable::Magic::_wizard which was called: # once (10µs+0s) by Variable::Magic::wizard at line 359
sub Variable::Magic::_wizard; # xsub
# spent 20µs (18+3) within Variable::Magic::cast which was called 2 times, avg 10µs/call: # 2 times (18µs+3µs) by B::Hooks::EndOfScope::XS::on_scope_end at line 45 of B/Hooks/EndOfScope/XS.pm, avg 10µs/call
sub Variable::Magic::cast; # xsub
# spent 1µs within Variable::Magic::getdata which was called 2 times, avg 550ns/call: # 2 times (1µs+0s) by B::Hooks::EndOfScope::XS::on_scope_end at line 41 of B/Hooks/EndOfScope/XS.pm, avg 550ns/call
sub Variable::Magic::getdata; # xsub