mixins

Following is the code I tried to run from the Ruby Programming Book http://www.ruby-doc.org/docs/ProgrammingRuby/html/tut_modules.html Why doesn't the product method give the right output? I ran it with irb test.rb . And I am running Ruby 1.9.3p194 . module Inject def inject(n) each do |value| n = yield(n, value) end n end def sum(initial = 0) inject(initial) { |n, value| n + value } end def product(initial = 1) inject(initial) { |n, value| n * value } end end class Array include Inject end [1, 2, 3, 4, 5].sum ## 15 [1, 2, 3, 4, 5].product ## [[1], [2], [3], [4], [5]] By the way: in Ruby 2.0,

I want to put info about one object in many views without repeating it in get_context_data in each view. As u understand i need a class with get_context_data inside, that i can mix with other views. Here in my example i want to see 'some_object' in context of UpdateAnotherObjectView: class BaseObjectInfoView(View): def get_context_data(self, **kwargs): context_data = super(BaseObjectInfoView, self).get_context_data(**kwargs) context_data['some_object'] = SomeObjects.objects.get(pk=1) return context_data class UpdateAnotherObjectView(BaseObjectInfo, UpdateView): template_name = 'create_object

I'm studying about mixins (in C++). I read some articles on mixins and found two different patterns of "approximating" mixins in C++. Pattern 1: template<class Base> struct Mixin1 : public Base { }; template<class Base> struct Mixin2 : public Base { }; struct MyType { }; typedef Mixin2<Mixin1<MyType>> MyTypeWithMixins; Pattern 2: (may be called CRTP) template<class T> struct Mixin1 { }; template<class T> struct Mixin2 { }; struct MyType { }; struct MyTypeWithMixins : public MyType, public Mixin1<MyTypeWithMixins>, public Mixin2<MyTypeWithMixins> { }; Are they equivalent practically? I'd like

From the Module Module#append_features(mod) → mod => When this module is included in another, Ruby calls append_features in this module, passing it the receiving module in mod. Ruby’s default implementation is to add the constants, methods, and module variables of this module to mod if this module has not already been added to mod or one of its ancestors. Module#prepend_features(mod) → mod => When this module is prepended in another, Ruby calls prepend_features in this module, passing it the receiving module in mod. Ruby’s default implementation is to overlay the constants, methods, and module