Profile of Variable/Magic.pm

Filename	/usr/lib/x86_64-linux-gnu/perl5/5.20/Variable/Magic.pm
Statements	Executed 30 statements in 1.08ms

Subroutines
Calls	P	F	Exclusive Time	Inclusive Time	Subroutine
1	1	1	19µs	26µs	Variable::Magic::::wizardVariable::Magic::wizard
1	1	1	18µs	18µs	Variable::Magic::::BEGIN@3Variable::Magic::BEGIN@3
1	1	1	11µs	69µs	Variable::Magic::::BEGIN@646Variable::Magic::BEGIN@646
1	1	1	9µs	10µs	Variable::Magic::::castVariable::Magic::cast (xsub)
1	1	1	8µs	168µs	Variable::Magic::::BEGIN@213Variable::Magic::BEGIN@213
1	1	1	7µs	7µs	Variable::Magic::::_wizardVariable::Magic::_wizard (xsub)
1	1	1	7µs	20µs	Variable::Magic::::BEGIN@5Variable::Magic::BEGIN@5
1	1	1	7µs	10µs	Variable::Magic::::BEGIN@6Variable::Magic::BEGIN@6
1	1	1	4µs	4µs	Variable::Magic::::BEGIN@19Variable::Magic::BEGIN@19
1	1	1	1µs	1µs	Variable::Magic::::getdataVariable::Magic::getdata (xsub)

Call graph for these subroutines as a Graphviz dot language file.

Line	State ments	Time on line	Calls	Time in subs	Code
1					package Variable::Magic;
2
3	2	42µs	1	18µs	# spent 18µs within Variable::Magic::BEGIN@3 which was called: # once (18µs+0s) by Module::Runtime::require_module at line 3 use 5.008; # spent 18µs making 1 call to Variable::Magic::BEGIN@3
4
5	2	24µs	2	33µs	# spent 20µs (7+13) within Variable::Magic::BEGIN@5 which was called: # once (7µs+13µs) by Module::Runtime::require_module at line 5 use strict; # spent 20µs making 1 call to Variable::Magic::BEGIN@5 # spent 13µs making 1 call to strict::import
6	2	46µs	2	14µs	# spent 10µs (7+4) within Variable::Magic::BEGIN@6 which was called: # once (7µs+4µs) by Module::Runtime::require_module at line 6 use warnings; # spent 10µs making 1 call to Variable::Magic::BEGIN@6 # spent 4µs making 1 call to warnings::import
7
8					=head1 NAME
9
10					Variable::Magic - Associate user-defined magic to variables from Perl.
11
12					=head1 VERSION
13
14					Version 0.55
15
16					=cut
17
18	1	100ns			our $VERSION;
19					# spent 4µs within Variable::Magic::BEGIN@19 which was called: # once (4µs+0s) by Module::Runtime::require_module at line 21 BEGIN {
20	1	4µs			$VERSION = '0.55';
21	1	122µs	1	4µs	} # spent 4µs 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					$h{pear} = 1; # "key pear stored in helem"
51					}
52
53					=head1 DESCRIPTION
54
55					Magic is Perl's way of enhancing variables.
56					This mechanism lets the user add extra data to any variable and hook syntactical operations (such as access, assignment or destruction) that can be applied to it.
57					With this module, you can add your own magic to any variable without having to write a single line of XS.
58
59					You'll realize that these magic variables look a lot like tied variables.
60					It is not surprising, as tied variables are implemented as a special kind of magic, just like any 'irregular' Perl variable : scalars like C<$!>, 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...
61					They all share the same underlying C API, and this module gives you direct access to it.
62
63					Still, the magic made available by this module differs from tieing and overloading in several ways :
64
65					=over 4
66
67					=item *
68
69					Magic is not copied on assignment.
70
71					You attach it to variables, not values (as for blessed references).
72
73					=item *
74
75					Magic does not replace the original semantics.
76
77					Magic callbacks usually get triggered before the original action takes place, and cannot prevent it from happening.
78					This 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
82					Magic is multivalued.
83
84					You can safely apply different kinds of magics to the same variable, and each of them will be invoked successively.
85
86					=item *
87
88					Magic is type-agnostic.
89
90					The same magic can be applied on scalars, arrays, hashes, subs or globs.
91					But the same hook (see below for a list) may trigger differently depending on the type of the variable.
92
93					=item *
94
95					Magic is invisible at Perl level.
96
97					Magical and non-magical variables cannot be distinguished with C<ref>, C<tied> or another trick.
98
99					=item *
100
101					Magic is notably faster.
102
103					Mainly because perl's way of handling magic is lighter by nature, and because there is no need for any method resolution.
104					Also, since you don't have to reimplement all the variable semantics, you only pay for what you actually use.
105
106					=back
107
108					The operations that can be overloaded are :
109
110					=over 4
111
112					=item *
113
114					I<get>
115
116					This magic is invoked when the variable is evaluated.
117					It is never called for arrays and hashes.
118
119					=item *
120
121					I<set>
122
123					This magic is called each time the value of the variable changes.
124					It is called for array subscripts and slices, but never for hashes.
125
126					=item *
127
128					I<len>
129
130					This 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.
131					This 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>).
132					The length is returned from the callback as an integer.
133
134					Starting 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.
135					You 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
139					I<clear>
140
141					This magic is invoked when the variable is reset, such as when an array is emptied.
142					Please 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
146					I<free>
147
148					This magic is called when a variable is destroyed as the result of going out of scope (but not when it is undefined).
149					It 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
153					I<copy>
154
155					When applied to tied arrays and hashes, this magic fires when you try to access or change their elements.
156
157					Starting from perl 5.17.0, it can also be applied to closure prototypes, in which case the magic will be called when the prototype is cloned.
158					The L</VMG_COMPAT_CODE_COPY_CLONE> constant is true when your perl support this feature.
159
160					=item *
161
162					I<dup>
163
164					This magic is invoked when the variable is cloned across threads.
165					It is currently not available.
166
167					=item *
168
169					I<local>
170
171					When this magic is set on a variable, all subsequent localizations of the variable will trigger the callback.
172					It is available on your perl if and only if C<MGf_LOCAL> is true.
173
174					=back
175
176					The following actions only apply to hashes and are available if and only if L</VMG_UVAR> is true.
177					They are referred to as I<uvar> magics.
178
179					=over 4
180
181					=item *
182
183					I<fetch>
184
185					This magic is invoked each time an element is fetched from the hash.
186
187					=item *
188
189					I<store>
190
191					This one is called when an element is stored into the hash.
192
193					=item *
194
195					I<exists>
196
197					This magic fires when a key is tested for existence in the hash.
198
199					=item *
200
201					I<delete>
202
203					This magic is triggered when a key is deleted in the hash, regardless of whether the key actually exists in it.
204
205					=back
206
207					You can refer to the tests to have more insight of where the different magics are invoked.
208
209					=head1 FUNCTIONS
210
211					=cut
212
213					# spent 168µs (8+161) within Variable::Magic::BEGIN@213 which was called: # once (8µs+161µs) by Module::Runtime::require_module at line 216 BEGIN {
214	1	400ns			require XSLoader;
215	1	167µs	1	161µs	XSLoader::load(__PACKAGE__, $VERSION); # spent 161µs making 1 call to XSLoader::load
216	1	359µs	1	168µs	} # spent 168µs making 1 call to Variable::Magic::BEGIN@213
217
218					=head2 C<wizard>
219
220					wizard(
221					data => sub { ... },
222					get => sub { my ($ref, $data [, $op]) = @_; ... },
223					set => sub { my ($ref, $data [, $op]) = @_; ... },
224					len => sub {
225					my ($ref, $data, $len [, $op]) = @_; ... ; return $newlen
226					},
227					clear => sub { my ($ref, $data [, $op]) = @_; ... },
228					free => sub { my ($ref, $data [, $op]) = @_, ... },
229					copy => sub { my ($ref, $data, $key, $elt [, $op]) = @_; ... },
230					local => sub { my ($ref, $data [, $op]) = @_; ... },
231					fetch => sub { my ($ref, $data, $key [, $op]) = @_; ... },
232					store => sub { my ($ref, $data, $key [, $op]) = @_; ... },
233					exists => sub { my ($ref, $data, $key [, $op]) = @_; ... },
234					delete => sub { my ($ref, $data, $key [, $op]) = @_; ... },
235					copy_key => $bool,
236					op_info => [ 0 \| VMG_OP_INFO_NAME \| VMG_OP_INFO_OBJECT ],
237					)
238
239					This function creates a 'wizard', an opaque object that holds the magic information.
240					It takes a list of keys / values as argument, whose keys can be :
241
242					=over 4
243
244					=item *
245
246					C<data>
247
248					A code (or string) reference to a private data constructor.
249					It is called in scalar context each time the magic is cast onto a variable, with C<$_[0]> being a reference to this variable and C<@_[1 .. @_-1]> being all extra arguments that were passed to L</cast>.
250					The scalar returned from this call is then attached to the variable and can be retrieved later with L</getdata>.
251
252					=item *
253
254					C<get>, C<set>, C<len>, C<clear>, C<free>, C<copy>, C<local>, C<fetch>, C<store>, C<exists> and C<delete>
255
256					Code (or string) references to the respective magic callbacks.
257					You don't have to specify all of them : the magic corresponding to undefined entries will simply not be hooked.
258
259					When 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).
260					Other arguments depend on which kind of magic is involved :
261
262					=over 8
263
264					=item *
265
266					I<len>
267
268					C<$_[2]> contains the natural, non-magical length of the variable (which can only be a scalar or an array as I<len> magic is only relevant for these types).
269					The callback is expected to return the new scalar or array length to use, or C<undef> to default to the normal length.
270
271					=item *
272
273					I<copy>
274
275					When the variable for which the magic is invoked is an array or an hash, C<$_[2]> is a either an alias or a copy of the current key, and C<$_[3]> is an alias to the current element (i.e. the value).
276					Since C<$_[2]> might be a copy, it is useless to try to change it or cast magic on it.
277
278					Starting from perl 5.17.0, this magic can also be called for code references.
279					In this case, C<$_[2]> is always C<undef> and C<$_[3]> is a reference to the cloned anonymous subroutine.
280
281					=item *
282
283					I<fetch>, I<store>, I<exists> and I<delete>
284
285					C<$_[2]> is an alias to the current key.
286					Note that C<$_[2]> may rightfully be readonly if the key comes from a bareword, and as such it is unsafe to assign to it.
287					You 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.
288
289					=back
290
291					Finally, if C<< op_info => $num >> is also passed to C<wizard>, then one extra element is appended to C<@_>.
292					Its nature depends on the value of C<$num> :
293
294					=over 8
295
296					=item *
297
298					C<VMG_OP_INFO_NAME>
299
300					C<$_[-1]> is the current op name.
301
302					=item *
303
304					C<VMG_OP_INFO_OBJECT>
305
306					C<$_[-1]> is the C<B::OP> object for the current op.
307
308					=back
309
310					Both result in a small performance hit, but just getting the name is lighter than getting the op object.
311
312					These callbacks are executed in scalar context and are expected to return an integer, which is then passed straight to the perl magic API.
313					However, only the return value of the I<len> magic callback currently holds a meaning.
314
315					=back
316
317					Each callback can be specified as :
318
319					=over 4
320
321					=item *
322
323					a code reference, which will be called as a subroutine.
324
325					=item *
326
327					a string reference, where the string denotes which subroutine is to be called when magic is triggered.
328					If the subroutine name is not fully qualified, then the current package at the time the magic is invoked will be used instead.
329
330					=item *
331
332					a reference to C<undef>, in which case a no-op magic callback is installed instead of the default one.
333					This may especially be helpful for I<local> magic, where an empty callback prevents magic from being copied during localization.
334
335					=back
336
337					Note 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.
338
339					Here is a simple usage example :
340
341					# A simple scalar tracer
342					my $wiz = wizard(
343					get => sub { print STDERR "got ${$_[0]}\n" },
344					set => sub { print STDERR "set to ${$_[0]}\n" },
345					free => sub { print STDERR "${$_[0]} was deleted\n" },
346					);
347
348					=cut
349
350					# spent 26µs (19+7) within Variable::Magic::wizard which was called: # once (19µs+7µs) by Module::Runtime::require_module at line 33 of B/Hooks/EndOfScope/XS.pm sub wizard {
351	1	900ns			if (@_ % 2) {
352					require Carp;
353					Carp::croak('Wrong number of arguments for wizard()');
354					}
355
356	1	2µs			my %opts = @_;
357
358	1	1µs			my @keys = qw<op_info data get set len clear free copy dup>;
359	1	400ns			push @keys, 'local' if MGf_LOCAL;
360	1	900ns			push @keys, qw<fetch store exists delete copy_key> if VMG_UVAR;
361
362	1	100ns			my ($wiz, $err);
363					{
364	2	400ns			local $@;
365	2	17µs	1	7µs	$wiz = eval { _wizard(map $opts{$_}, @keys) }; # spent 7µs making 1 call to Variable::Magic::_wizard
366	1	500ns			$err = $@;
367					}
368	1	200ns			if ($err) {
369					$err =~ s/\sat\s+.*?\n//;
370					require Carp;
371					Carp::croak($err);
372					}
373
374	1	4µs			return $wiz;
375					}
376
377					=head2 C<cast>
378
379					cast [$@%&*]var, $wiz, @args
380
381					This function associates C<$wiz> magic to the supplied variable, without overwriting any other kind of magic.
382					It returns true on success or when C<$wiz> magic is already attached, and croaks on error.
383					When C<$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]>.
384					Otherwise, C<@args> is ignored.
385
386					# Casts $wiz onto $x, passing (\$x, '1') to the data constructor.
387					my $x;
388					cast $x, $wiz, 1;
389
390					The C<var> argument can be an array or hash value.
391					Magic for these scalars behaves like for any other, except that it is dispelled when the entry is deleted from the container.
392					For example, if you want to call C<POSIX::tzset> each time the C<'TZ'> environment variable is changed in C<%ENV>, you can use :
393
394					use POSIX;
395					cast $ENV{TZ}, wizard set => sub { POSIX::tzset(); () };
396
397					If you want to handle the possible deletion of the C<'TZ'> entry, you must also specify I<store> magic.
398
399					=head2 C<getdata>
400
401					getdata [$@%&*]var, $wiz
402
403					This accessor fetches the private data associated with the magic C<$wiz> in the variable.
404					It 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.
405
406					# Get the data attached to $wiz in $x, or undef if $wiz
407					# did not attach any.
408					my $data = getdata $x, $wiz;
409
410					=head2 C<dispell>
411
412					dispell [$@%&*]variable, $wiz
413
414					The exact opposite of L</cast> : it dissociates C<$wiz> magic from the variable.
415					This 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.
416
417					# Dispell now.
418					die 'no such magic in $x' unless dispell $x, $wiz;
419
420					=head1 CONSTANTS
421
422					=head2 C<MGf_COPY>
423
424					Evaluates to true if and only if the I<copy> magic is available.
425					This is the case for perl 5.7.3 and greater, which is ensured by the requirements of this module.
426
427					=head2 C<MGf_DUP>
428
429					Evaluates to true if and only if the I<dup> magic is available.
430					This is the case for perl 5.7.3 and greater, which is ensured by the requirements of this module.
431
432					=head2 C<MGf_LOCAL>
433
434					Evaluates to true if and only if the I<local> magic is available.
435					This is the case for perl 5.9.3 and greater.
436
437					=head2 C<VMG_UVAR>
438
439					When this constant is true, you can use the I<fetch>, I<store>, I<exists> and I<delete> magics on hashes.
440					Initial L</VMG_UVAR> capability was introduced in perl 5.9.5, with a fully functional implementation shipped with perl 5.10.0.
441
442					=head2 C<VMG_COMPAT_SCALAR_LENGTH_NOLEN>
443
444					True for perls that don't call I<len> magic when taking the C<length> of a magical scalar.
445
446					=head2 C<VMG_COMPAT_SCALAR_NOLEN>
447
448					True for perls that don't call I<len> magic on scalars.
449					Implies L</VMG_COMPAT_SCALAR_LENGTH_NOLEN>.
450
451					=head2 C<VMG_COMPAT_ARRAY_PUSH_NOLEN>
452
453					True for perls that don't call I<len> magic when you push an element in a magical array.
454					Starting from perl 5.11.0, this only refers to pushes in non-void context and hence is false.
455
456					=head2 C<VMG_COMPAT_ARRAY_PUSH_NOLEN_VOID>
457
458					True for perls that don't call I<len> magic when you push in void context an element in a magical array.
459
460					=head2 C<VMG_COMPAT_ARRAY_UNSHIFT_NOLEN_VOID>
461
462					True for perls that don't call I<len> magic when you unshift in void context an element in a magical array.
463
464					=head2 C<VMG_COMPAT_ARRAY_UNDEF_CLEAR>
465
466					True for perls that call I<clear> magic when undefining magical arrays.
467
468					=head2 C<VMG_COMPAT_HASH_DELETE_NOUVAR_VOID>
469
470					True for perls that don't call I<delete> magic when you delete an element from a hash in void context.
471
472					=head2 C<VMG_COMPAT_CODE_COPY_CLONE>
473
474					True for perls that call I<copy> magic when a magical closure prototype is cloned.
475
476					=head2 C<VMG_COMPAT_GLOB_GET>
477
478					True for perls that call I<get> magic for operations on globs.
479
480					=head2 C<VMG_PERL_PATCHLEVEL>
481
482					The perl patchlevel this module was built with, or C<0> for non-debugging perls.
483
484					=head2 C<VMG_THREADSAFE>
485
486					True if and only if this module could have been built with thread-safety features enabled.
487
488					=head2 C<VMG_FORKSAFE>
489
490					True if and only if this module could have been built with fork-safety features enabled.
491					This is always true except on Windows where it is false for perl 5.10.0 and below.
492
493					=head2 C<VMG_OP_INFO_NAME>
494
495					Value to pass with C<op_info> to get the current op name in the magic callbacks.
496
497					=head2 C<VMG_OP_INFO_OBJECT>
498
499					Value to pass with C<op_info> to get a C<B::OP> object representing the current op in the magic callbacks.
500
501					=head1 COOKBOOK
502
503					=head2 Associate an object to any perl variable
504
505					This technique can be useful for passing user data through limited APIs.
506					It is similar to using inside-out objects, but without the drawback of having to implement a complex destructor.
507
508					{
509					package Magical::UserData;
510
511					use Variable::Magic qw<wizard cast getdata>;
512
513					my $wiz = wizard data => sub { \$_[1] };
514
515					sub ud (\[$@%*&]) : lvalue {
516					my ($var) = @_;
517					my $data = &getdata($var, $wiz);
518					unless (defined $data) {
519					$data = \(my $slot);
520					&cast($var, $wiz, $slot)
521					or die "Couldn't cast UserData magic onto the variable";
522					}
523					$$data;
524					}
525					}
526
527					{
528					BEGIN { *ud = \&Magical::UserData::ud }
529
530					my $cb;
531					$cb = sub { print 'Hello, ', ud(&$cb), "!\n" };
532
533					ud(&$cb) = 'world';
534					$cb->(); # Hello, world!
535					}
536
537					=head2 Recursively cast magic on datastructures
538
539					C<cast> can be called from any magical callback, and in particular from C<data>.
540					This allows you to recursively cast magic on datastructures :
541
542					my $wiz;
543					$wiz = wizard data => sub {
544					my ($var, $depth) = @_;
545					$depth \|\|= 0;
546					my $r = ref $var;
547					if ($r eq 'ARRAY') {
548					&cast((ref() ? $_ : \$_), $wiz, $depth + 1) for @$var;
549					} elsif ($r eq 'HASH') {
550					&cast((ref() ? $_ : \$_), $wiz, $depth + 1) for values %$var;
551					}
552					return $depth;
553					},
554					free => sub {
555					my ($var, $depth) = @_;
556					my $r = ref $var;
557					print "free $r at depth $depth\n";
558					();
559					};
560
561					{
562					my %h = (
563					a => [ 1, 2 ],
564					b => { c => 3 }
565					);
566					cast %h, $wiz;
567					}
568
569					When C<%h> goes out of scope, this prints something among the lines of :
570
571					free HASH at depth 0
572					free HASH at depth 1
573					free SCALAR at depth 2
574					free ARRAY at depth 1
575					free SCALAR at depth 3
576					free SCALAR at depth 3
577
578					Of course, this example does nothing with the values that are added after the C<cast>.
579
580					=head1 PERL MAGIC HISTORY
581
582					The places where magic is invoked have changed a bit through perl history.
583					Here is a little list of the most recent ones.
584
585					=over 4
586
587					=item *
588
589					B<5.6.x>
590
591					I<p14416> : I<copy> and I<dup> magic.
592
593					=item *
594
595					B<5.8.9>
596
597					I<p28160> : Integration of I<p25854> (see below).
598
599					I<p32542> : Integration of I<p31473> (see below).
600
601					=item *
602
603					B<5.9.3>
604
605					I<p25854> : I<len> magic is no longer called when pushing an element into a magic array.
606
607					I<p26569> : I<local> magic.
608
609					=item *
610
611					B<5.9.5>
612
613					I<p31064> : Meaningful I<uvar> magic.
614
615					I<p31473> : I<clear> magic was not invoked when undefining an array.
616					The bug is fixed as of this version.
617
618					=item *
619
620					B<5.10.0>
621
622					Since 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.
623
624					=item *
625
626					B<5.11.x>
627
628					I<p32969> : I<len> magic is no longer invoked when calling C<length> with a magical scalar.
629
630					I<p34908> : I<len> magic is no longer called when pushing / unshifting an element into a magical array in void context.
631					The C<push> part was already covered by I<p25854>.
632
633					I<g9cdcb38b> : I<len> magic is called again when pushing into a magical array in non-void context.
634
635					=back
636
637					=head1 EXPORT
638
639					The functions L</wizard>, L</cast>, L</getdata> and L</dispell> are only exported on request.
640					All of them are exported by the tags C<':funcs'> and C<':all'>.
641
642					All the constants are also only exported on request, either individually or by the tags C<':consts'> and C<':all'>.
643
644					=cut
645
646	2	272µs	2	126µs	# spent 69µs (11+58) within Variable::Magic::BEGIN@646 which was called: # once (11µs+58µs) by Module::Runtime::require_module at line 646 use base qw<Exporter>; # spent 69µs making 1 call to Variable::Magic::BEGIN@646 # spent 58µs making 1 call to base::import
647
648	1	500ns			our @EXPORT = ();
649	1	4µs			our %EXPORT_TAGS = (
650					'funcs' => [ qw<wizard cast getdata dispell> ],
651					'consts' => [ qw<
652					MGf_COPY MGf_DUP MGf_LOCAL VMG_UVAR
653					VMG_COMPAT_SCALAR_LENGTH_NOLEN
654					VMG_COMPAT_SCALAR_NOLEN
655					VMG_COMPAT_ARRAY_PUSH_NOLEN VMG_COMPAT_ARRAY_PUSH_NOLEN_VOID
656					VMG_COMPAT_ARRAY_UNSHIFT_NOLEN_VOID
657					VMG_COMPAT_ARRAY_UNDEF_CLEAR
658					VMG_COMPAT_HASH_DELETE_NOUVAR_VOID
659					VMG_COMPAT_CODE_COPY_CLONE
660					VMG_COMPAT_GLOB_GET
661					VMG_PERL_PATCHLEVEL
662					VMG_THREADSAFE VMG_FORKSAFE
663					VMG_OP_INFO_NAME VMG_OP_INFO_OBJECT
664					> ],
665					);
666	1	6µs			our @EXPORT_OK = map { @$_ } values %EXPORT_TAGS;
667	1	2µs			$EXPORT_TAGS{'all'} = [ @EXPORT_OK ];
668
669					=head1 CAVEATS
670
671					In order to hook hash operations with magic, you need at least perl 5.10.0 (see L</VMG_UVAR>).
672
673					If 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.
674					You can work around this gotcha by storing a reference to the magic object instead.
675
676					If 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.
677
678					=head1 DEPENDENCIES
679
680					L<perl> 5.8.
681
682					A C compiler.
683					This 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.
684
685					L<Carp> (core since perl 5), L<XSLoader> (since 5.6.0).
686
687					=head1 SEE ALSO
688
689					L<perlguts> and L<perlapi> for internal information about magic.
690
691					L<perltie> and L<overload> for other ways of enhancing objects.
692
693					=head1 AUTHOR
694
695					Vincent Pit, C<< <perl at profvince.com> >>, L<http://www.profvince.com>.
696
697					You can contact me by mail or on C<irc.perl.org> (vincent).
698
699					=head1 BUGS
700
701					Please 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>.
702					I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.
703
704					=head1 SUPPORT
705
706					You can find documentation for this module with the perldoc command.
707
708					perldoc Variable::Magic
709
710					Tests code coverage report is available at L<http://www.profvince.com/perl/cover/Variable-Magic>.
711
712					=head1 COPYRIGHT & LICENSE
713
714					Copyright 2007,2008,2009,2010,2011,2012,2013,2014 Vincent Pit, all rights reserved.
715
716					This program is free software; you can redistribute it and/or modify it
717					under the same terms as Perl itself.
718
719					=cut
720
721	1	5µs			1; # End of Variable::Magic

					# spent 7µs within Variable::Magic::_wizard which was called: # once (7µs+0s) by Variable::Magic::wizard at line 365 sub Variable::Magic::_wizard; # xsub
					# spent 10µs (9+1) within Variable::Magic::cast which was called: # once (9µs+1µs) by B::Hooks::EndOfScope::XS::on_scope_end at line 45 of B/Hooks/EndOfScope/XS.pm sub Variable::Magic::cast; # xsub
					# spent 1µs within Variable::Magic::getdata which was called: # once (1µs+0s) by B::Hooks::EndOfScope::XS::on_scope_end at line 41 of B/Hooks/EndOfScope/XS.pm sub Variable::Magic::getdata; # xsub