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.\" Automatically generated by Pod::Man 2.16 (Pod::Simple 3.05).\".\" Standard preamble:.\" ========================================================================.de Sh \" Subsection heading.br.if t .Sp.ne 5.PP\fB\\$1\fR.PP...de Sp \" Vertical space (when we can't use .PP).if t .sp .5v.if n .sp...de Vb \" Begin verbatim text.ft CW.nf.ne \\$1...de Ve \" End verbatim text.ft R.fi...\" Set up some character translations and predefined strings. \*(-- will.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left.\" double quote, and \*(R" will give a right double quote. \*(C+ will.\" give a nicer C++. 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Of course, you'll have to process the.\" output yourself in some meaningful fashion..ie \nF \{\. de IX. tm Index:\\$1\t\\n%\t"\\$2"... nr % 0. rr F.\}.el \{\. de IX...\}.\".\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2)..\" Fear. Run. Save yourself. No user-serviceable parts.. \" fudge factors for nroff and troff.if n \{\. ds #H 0. ds #V .8m. ds #F .3m. ds #[ \f1. ds #] \fP.\}.if t \{\. ds #H ((1u-(\\\\n(.fu%2u))*.13m). ds #V .6m. ds #F 0. ds #[ \&. ds #] \&.\}. \" simple accents for nroff and troff.if n \{\. ds ' \&. ds ` \&. ds ^ \&. ds , \&. ds ~ ~. ds /.\}.if t \{\. ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u". ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'. ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'. ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'. ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'. ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'.\}. \" troff and (daisy-wheel) nroff accents.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'.ds 8 \h'\*(#H'\(*b\h'-\*(#H'.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#].ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#].ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#].ds ae a\h'-(\w'a'u*4/10)'e.ds Ae A\h'-(\w'A'u*4/10)'E. \" corrections for vroff.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'. \" for low resolution devices (crt and lpr).if \n(.H>23 .if \n(.V>19 \\{\. ds : e. ds 8 ss. ds o a. ds d- d\h'-1'\(ga. ds D- D\h'-1'\(hy. ds th \o'bp'. ds Th \o'LP'. ds ae ae. ds Ae AE.\}.rm #[ #] #H #V #F C.\" ========================================================================.\".IX Title "base 3".TH base 3 "2007-12-18" "perl v5.10.0" "Perl Programmers Reference Guide".\" For nroff, turn off justification. Always turn off hyphenation; it makes.\" way too many mistakes in technical documents..if n .ad l.nh.SH "NAME"base \- Establish an ISA relationship with base classes at compile time.SH "SYNOPSIS".IX Header "SYNOPSIS".Vb 2\& package Baz;\& use base qw(Foo Bar);.Ve.SH "DESCRIPTION".IX Header "DESCRIPTION"Allows you to both load one or more modules, while setting up inheritance fromthose modules at the same time. Roughly similar in effect to.PP.Vb 6\& package Baz;\& BEGIN {\& require Foo;\& require Bar;\& push @ISA, qw(Foo Bar);\& }.Ve.PP\&\f(CW\*(C`base\*(C'\fR employs some heuristics to determine if a module has already beenloaded, if it has it doesn't try again. If \f(CW\*(C`base\*(C'\fR tries to \f(CW\*(C`require\*(C'\fR themodule it will not die if it cannot find the module's file, but will die on anyother error. After all this, should your base class be empty, containing nosymbols, it will die. This is useful for inheriting from classes in the samefile as yourself, like so:.PP.Vb 2\& package Foo;\& sub exclaim { "I can have such a thing?!" }\& \& package Bar;\& use base "Foo";.Ve.PPIf \f(CW$VERSION\fR is not detected even after loading it, <base> will define \f(CW$VERSION\fRin the base package, setting it to the string \f(CW\*(C`\-1, set by base.pm\*(C'\fR..PP\&\f(CW\*(C`base\*(C'\fR will also initialize the fields if one of the base classes has it.Multiple inheritance of fields is \fB\s-1NOT\s0\fR supported, if two or more base classeseach have inheritable fields the 'base' pragma will croak. See fields,public and protected for a description of this feature..PPThe base class' \f(CW\*(C`import\*(C'\fR method is \fBnot\fR called..SH "DIAGNOSTICS".IX Header "DIAGNOSTICS".ie n .IP "Base class package ""%s"" is empty." 4.el .IP "Base class package ``%s'' is empty." 4.IX Item "Base class package %s is empty."base.pm was unable to require the base package, because it was notfound in your path..IP "Class 'Foo' tried to inherit from itself" 4.IX Item "Class 'Foo' tried to inherit from itself"Attempting to inherit from yourself generates a warning..Sp.Vb 2\& use Foo;\& use base \*(AqFoo\*(Aq;.Ve.SH "HISTORY".IX Header "HISTORY"This module was introduced with Perl 5.004_04..SH "CAVEATS".IX Header "CAVEATS"Due to the limitations of the implementation, you must usebase \fIbefore\fR you declare any of your own fields..SH "SEE ALSO".IX Header "SEE ALSO"fields
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