No need to check class definition

Because now the `Struct` class is always defined when this file is included.

mrbgems/mruby-struct/mrblib/struct.rb

@@ -2,99 +2,96 @@
 # Struct
 #
 # ISO 15.2.18
+class Struct
 
-if Object.const_defined?(:Struct)
-  class Struct
+  ##
+  # Calls the given block for each element of +self+
+  # and pass the respective element.
+  #
+  # ISO 15.2.18.4.4
+  def each(&block)
+    self.class.members.each{|field|
+      block.call(self[field])
+    }
+    self
+  end
 
-    ##
-    # Calls the given block for each element of +self+
-    # and pass the respective element.
-    #
-    # ISO 15.2.18.4.4
-    def each(&block)
-      self.class.members.each{|field|
-        block.call(self[field])
-      }
-      self
+  ##
+  # Calls the given block for each element of +self+
+  # and pass the name and value of the respective
+  # element.
+  #
+  # ISO 15.2.18.4.5
+  def each_pair(&block)
+    self.class.members.each{|field|
+      block.call(field.to_sym, self[field])
+    }
+    self
+  end
+
+  ##
+  # Calls the given block for each element of +self+
+  # and returns an array with all elements of which
+  # block is not false.
+  #
+  # ISO 15.2.18.4.7
+  def select(&block)
+    ary = []
+    self.class.members.each{|field|
+      val = self[field]
+      ary.push(val) if block.call(val)
+    }
+    ary
+  end
+
+  def _inspect(recur_list)
+    return "#<struct #{self.class}:...>" if recur_list[self.object_id]
+    recur_list[self.object_id] = true
+    name = self.class.to_s
+    if name[0] == "#"
+      str = "#<struct "
+    else
+      str = "#<struct #{name} "
     end
-
-    ##
-    # Calls the given block for each element of +self+
-    # and pass the name and value of the respective
-    # element.
-    #
-    # ISO 15.2.18.4.5
-    def each_pair(&block)
-      self.class.members.each{|field|
-        block.call(field.to_sym, self[field])
-      }
-      self
+    buf = []
+    self.each_pair do |k,v|
+      buf.push k.to_s + "=" + v._inspect(recur_list)
     end
+    str + buf.join(", ") + ">"
+  end
 
-    ##
-    # Calls the given block for each element of +self+
-    # and returns an array with all elements of which
-    # block is not false.
-    #
-    # ISO 15.2.18.4.7
-    def select(&block)
-      ary = []
-      self.class.members.each{|field|
-        val = self[field]
-        ary.push(val) if block.call(val)
-      }
-      ary
-    end
+  ##
+  # call-seq:
+  #   struct.to_s      -> string
+  #   struct.inspect   -> string
+  #
+  # Describe the contents of this struct in a string.
+  #
+  # 15.2.18.4.10(x)
+  #
+  def inspect
+    self._inspect({})
+  end
 
-    def _inspect(recur_list)
-      return "#<struct #{self.class}:...>" if recur_list[self.object_id]
-      recur_list[self.object_id] = true
-      name = self.class.to_s
-      if name[0] == "#"
-        str = "#<struct "
-      else
-        str = "#<struct #{name} "
-      end
-      buf = []
-      self.each_pair do |k,v|
-        buf.push k.to_s + "=" + v._inspect(recur_list)
-      end
-      str + buf.join(", ") + ">"
-    end
+  ##
+  # 15.2.18.4.11(x)
+  #
+  alias to_s inspect
 
-    ##
-    # call-seq:
-    #   struct.to_s      -> string
-    #   struct.inspect   -> string
-    #
-    # Describe the contents of this struct in a string.
-    #
-    # 15.2.18.4.10(x)
-    #
-    def inspect
-      self._inspect({})
-    end
-
-    ##
-    # 15.2.18.4.11(x)
-    #
-    alias to_s inspect
-
-    ##
-    # call-seq:
-    #   hsh.dig(key,...)                 -> object
-    #
-    # Extracts the nested value specified by the sequence of <i>key</i>
-    # objects by calling +dig+ at each step, returning +nil+ if any
-    # intermediate step is +nil+.
-    #
-    def dig(idx,*args)
-      n = self[idx]
-      if args.size > 0
-        n&.dig(*args)
-      else
-        n
-      end
+  ##
+  # call-seq:
+  #   hsh.dig(key,...)                 -> object
+  #
+  # Extracts the nested value specified by the sequence of <i>key</i>
+  # objects by calling +dig+ at each step, returning +nil+ if any
+  # intermediate step is +nil+.
+  #
+  def dig(idx,*args)
+    n = self[idx]
+    if args.size > 0
+      n&.dig(*args)
+    else
+      n
     end
   end
 end