Use define_method instead of class_eval

Author: marcandre

lib/rspec/core/configuration.rb

@@ -75,11 +75,9 @@ def self.define_alias(name, alias_name)
 
       # @private
       def self.define_predicate(name)
-        class_eval <<-PREDICATE, __FILE__ , __LINE__ + 1
-          def #{name}?
-            !!#{name}
-          end
-        PREDICATE
+        define_method "#{name}?" do
+          !!send(name)
+        end
       end
 
       # @private