Optimized unit constructor on Numeric class

Gemfile

@@ -1,4 +1,4 @@
-source :rubygems
+source 'https://rubygems.org'
 
 # Specify your gem's dependencies in quantity.gemspec
 gemspec

lib/quantity.rb

@@ -371,16 +371,3 @@ def respond_to?(method)
     end
 
 end
-
-# @private
-# Plug our constructors into Numeric
-class Numeric
-  alias_method :quantity_method_missing, :method_missing
-  def method_missing(method, *args, &block)
-    if Quantity::Unit.is_unit?(method)
-      Quantity.new(self,Quantity::Unit.for(method))
-    else
-      quantity_method_missing(method,*args, &block)
-    end
-  end
-end

lib/quantity/unit.rb

@@ -42,13 +42,26 @@ def self.is_unit?(to)
       to.is_a?(Unit) || @@units.has_key?(to)
     end
 
+    # Plug unit constructor into Numeric, to support things like `1.lb`
+    # @param [Unit, String]
+    def self.add_numeric_helper(unit, name)
+      Numeric.class_eval do
+        unless method_defined?(name)
+          define_method name do
+            Quantity.new(self, unit)
+          end
+        end
+      end
+    end
+
     # Register a unit with the given symbols
     # @param [Unit] unit
     # @param [*names]
     def self.add_alias(unit,*names)
       unit = Unit.for(unit) unless unit.is_a? Unit
       names.each do |name|
         @@units[name] = unit
+        add_numeric_helper(unit, name)
       end
     end