--- module_eval(expr, [fname, [lineno=1]])
--- module_eval {|mod| .... }

    ⥸塼ΥƥȤʸ expr ɾƤη̤
    ޤ
    fnamelineno Ϳ줿ϡե fname
    ֹ lineno ˤʸ󤬤뤫Τ褦˥ѥ뤵졢
    åȥ졼ɽʤɤΥեֹ̾򺹤ؤ뤳ȤǤ
    

    ֥åͿ줿ˤϤΥ֥å⥸塼Υƥ
    ɾƤη̤֤ޤ֥åΰ mod ˤ
    self Ϥޤ

    ⥸塼ΥƥȤɾȤϡ¹椽Υ⥸塼뤬
    self ˤʤȤȤǤĤޤꡢΥ⥸塼ʸ
    ˤ뤫Τ褦˼¹Ԥޤ

    ѿ module_eval γ¦Υפȶͭ
    ޤruby 1.6 feature: version 1.6.8 ʹߡ饹ѿ
    Υפ⳰¦Υפˤʤޤ

    ((**)): module_eval Υ֥åǥ᥽åɤ硢
    instance_eval Ʊͤ¤ޤܺ٤Ϥ
    򻲾ȤƤ

    Object#instance_eval [Object/instance_eval],
    Module#class_eval [Module/class_eval]
    Module.new ⻲ȤƤ

