G'day all, I have a Player class, which inherits from an ArmedHumanoids class, which inherits in turn from a Humanoids class. Where and when should I create the Player object so that it is accessible in all my other classes - for example, a selectPlayerRace class? I know that by extending the Player class it becomes accessible, but I...
If you have Class A with an instance var "foo" which has a @property/@synthesize directive, and Class B inherits from Class A, does it also need to @property/@synthesize "foo"? The reason I ask is because when I try to use Class B's "foo", the calling class says that "foo" is not something of a structured union or a member, which makes m...
I'm writing documentation for an object-oriented language, and I wonder what kind of classes would be a good example for inheritance. Some common examples: class Person { } class Employee extends Person { } Currently my favorite, but I don't like Person->Employee because 'Employee' does not exactly look like fun. class Bicycle { } c...
I have a token class that looks something like this: class Token { public: typedef enum { STRTOK, INTTOK } Type; virtual bool IsA(Type) = 0; } class IntTok : public Token { int data; public: bool IsA(Type t) { return (t == INTTOK); } int GetData() { return data; } } IntTok newToken; if ( newToken.IsA(Token::INTTOK ) {...
Trying to understand super(). From the looks of it, both child classes can be created just fine. Im curious as to what difference there actually is in this code: class Base(object): def __init__(self): print "Base created" class ChildA(Base): def __init__(self): Base.__init__(self) class ChildB(Base): def _...
I am currently looking to make my own collection, which would be just like a regular list, except that it would only hold 10 items. If an item was added when there were already 10 items in the list, then the first item would be removed before the new item was appended. What I want to do is create a class that extends System.Collections....
Hi guys, I have a file: Base.h class Base; class DerivedA : public Base; class DerivedB : public Base; /*etc...*/ and another file: BaseFactory.h #include "Base.h" class BaseFactory { public: BaseFactory(const string }; Base * Create() { if(msClassName == "DerivedA") { return new DerivedA(); } else i...
How would someone join two classes each with independant inheritance trees to bridge context boundaries, given the restrictions that nether class's inheritance trees can be modified to inherit from the other ie if a item that is an entity saved to a database lets say public class Stockitem : StockItemBase { ... } needs to be display...
If I have a code like this: struct A { virtual void f(int) {} virtual void f(void*) {} }; struct B : public A { void f(int) {} }; struct C : public B { void f(void*) {} }; int main() { C c; c.f(1); return 0; } I get an error that says that I am trying to do an invalid conversion from int to void*. Why can't compiler...
Hi, I'm having issues with a very strange error in some code I wrote. The basic idea behind the code can be trivialised in the following example: template <class f, class g> class Ptr; template <class a, class b, class c = Ptr<a,b> > class Base { public: Base(){}; }; template <class d, class e> class Derived : public Base <d,...
I have a UserControl that is working fine. It is declared like this. public partial class DynamicList : System.Web.UI.UserControl { protected static BaseListController m_GenericListController = null; public DynamicList() { m_GenericListController = new GenericListController(this); } } Now I...
Yet another TFrame IDE-registered-component question from me. Thanks for all the help, fellow programmers. : ) Playing around with Darrian's TFrame inheritance suggestion here: Specifics: Basically, I have a TFrame-based component that I've registered to the IDE, and it has worked wonderfully. I'm now developing a few "sister" compo...
Every once in a while when I am tweaking my TFrame classes (adding properties, methods, etc), the IDE gets confused and acts as if it thinks the frame is a form, complete with header/caption, borders, etc. Yet, clearly the class is declared as a TFrame descendent. Any ideas as to what causes this, how to prevent, and how to fix? I'm...
Say i have a <table> with a css class defined (<table class="x">) and i want to change the 'color' property of just the first level of <td>, is this possible using css without setting classes on the relevant <td>? I.e. <table class="x"><tr><td> xxxx <table><tr><td>yyy</td><tr></table> </td></tr><table> I only want the xxxx to ch...
I have a class, lets call it A, and within that class definition I have the following: static QPainterPath *path; Which is to say, I'm declaring a static (class-wide) pointer to a path object; all instances of this class will now have the same shared data member. I would like to be able to build upon this class, subclassing it into mo...
Has anyone really wanted and used inheritance support on ORM tools, and if yes which one do you think offers the best support? Or is ORM Inheritance a "pie in the sky" concept? ...
I'm writing a program in C# that has a custom collection. The custom collection performs some useful aggregate functions (AllSuccessful, %Successful, etc) over it's members which are of type ResultInfo. I have several classes that derive from ResultInfo (UploadResultInfo, XUploadResultInfo, and YUploadResultInfo), and would like to hav...
Suppose I have a Base class: class Base { friend SomeOtherClass; }; And there is another (different) class that inherits from Base: class AnotherClass : public Base {} Is friendship inherited as well? Thank you ...
Is it OK to have a static member variable defined in a base class, and having several derived classes each using its own instance of this member variable? The following code compiles successfully, and prints the right output, but I am still not sure that doing something like that is a good practice. In the following example, how can it ...
I was reading on the sealed keyword in C#. I cant remember the last time i inherit from a standard library. In c++ I remember inheriting an std interface that typedef a few types and used some of my parameters. But that is 1) Trivial 2) An interface From the top of my head, i dont remember any class that i inherited that didnt have a vi...