NAME

       Check::ISA - DWIM, correct checking of an object's class

SYNOPSIS

               use Check::ISA;

               if ( obj($foo, "SomeClass") ) {
                       $foo->some_method;
               }

               # instead of one of these methods:
               UNIVERSAL::isa($foo, "SomeClass") # WRONG
               ref $obj eq "SomeClass"; # VERY WRONG
               $foo->isa("SomeClass") # May die
               local $@; eval { $foo->isa("SomeClass") } # too long

DESCRIPTION

       This module provides several functions to assist in testing whether a value is an object, and if so
       asking about its class.

FUNCTIONS

       obj $thing, [ $class ]
           This function tests if $thing is an object.

           If $class is provided, it also tests tests whether "$thing->isa($class)".

           $thing  is considered an object if it's blessed, or if it's a "GLOB" with a valid "IO" slot (the "IO"
           slot contains a FileHandle object which  is  the  actual  invocant).  This  corresponds  directly  to
           "gv_fetchmethod".

       obj_does $thing, [ $class_or_role ]
           Just like "obj" but uses "DOES" in UNIVERSAL instead of "isa" in UNIVERSAL.

           "DOES" in UNIVERSAL is just like "isa", except it's use is encouraged to query about an interface, as
           opposed to the object structure. If "DOES" is not overridden by th ebject, calling it is semantically
           identical to calling "isa".

           This is probably reccomended over "obj" for interoperability, but can be slower on Perls before 5.10.

           Note that "DOES" in UNIVERSAL

       inv $thing, [ $class_or_role ]
           Just like "obj_does", but also returns true for classes.

           Note that this method is slower, but is supposed to return true for any value you can call methods on
           (class, object, filehandle, etc).

           Look into autobox if you would like to be able to call methods on all values.

       obj_can $thing, $method
       inv_can $thing, $method
           Checks if $thing is an object or class, and calls "can" on $thing if appropriate.

SEE ALSO

       UNIVERSAL, Params::Util, autobox, Moose, asa

VERSION CONTROL

       This    module    is    maintained    using    Darcs.    You    can   get   the   latest   version   from
       <http://nothingmuch.woobling.org/code>, and use "darcs send" to commit changes.

AUTHOR

       Yuval Kogman <nothingmuch@woobling.org>

COPYRIGHT

               Copyright (c) 2008 Yuval Kogman. All rights reserved
               This program is free software; you can redistribute
               it and/or modify it under the same terms as Perl itself.

perl v5.10.0                                       2008-07-25                                    Check::ISA(3pm)