As I understand it, what makes dynamic cast different from a static cast is its use of RTTI, and the fact that it fails if the dynamic type of a variable- when casting from base to derived- does not fit. But why does the class have to be polymorphic for that to be done if we have the RTTI anyway? EDIT: Since there was some confusion abo...
Hello, I have a base class which has two child classes derived from it. class A {}; class B : public A {}; class C : public A {}; I have another class that has a pointer to collection of class A members using a vector, something like this: vector<A*> *m_collection; And what I do is to create objects of class B or C and add them to...
Does the extended RTTI in Delphi 2010 offer a way to list defined Class and Record Helpers at run time? As far as I know Delphi does not show a hint or warning when more than one class helper is defined for a class, class helper detection might be a helpful routine in 'quality assurance'. p.s. of course I know I should never ever use t...
Say B and C are derived from A. I want to be able to test whether any two instances of classes derived from A are instances of the same class, that is, whether A* foo and A* bar both point to B instances, without using RTTI. My current solution is something like this: class A { protected: typedef uintptr_t Code; virtual Code co...
I'm trying to use RTTI to add an event handler to a control, that may already have an event handler set. The code looks something like this: var prop: TRttiProperty; val: TValue; begin prop := FContext.GetType(MyControl.ClassInfo).GetProperty('OnChange'); val := prop.GetValue(MyControl); FOldOnChange := val.AsType<TNotifyEvent...
This is heavily simplified for the sake of the question. Say I have a hierarchy: struct Base { virtual int precision() const = 0; }; template<int Precision> struct Derived : public Base { typedef Traits<Precision>::Type Type; Derived(Type data) : value(data) {} virtual int precision() const { return Precision; } ...
I've noticed that reflection is one feature that developers from other languages find very lacking in c++. For certain applications I can really see why! It is so much easier to write things like an IDE's auto-complete if you had reflection. And certainly serialization APIs would be a world easier if we had it. On the other side, one of...
I want to convert an string to an enum type using TValue, I googled but I didn't find how to do that. type TEnumTest = (etFirst, etSecond); var D: TEnumTest; begin D := StrToENumTest('etFirst'); end; function StrToEnumTest(pStr:String):TEnumTest; var V: TValue; begin V := TValue.From<String>(pstr); Result := V.AsType<TE...
hello, how to extract RTTI info about methods in Delphi records? is it possible by using new Rtti unit? ...
Please forgive the verbosity of the following code example. Using Delphi 2009, I created the two classes TOtherClass and TMyClass: TOtherClass = class(TObject) public FData: string; end; TMyClass = class(TObject) private FIndxPropList: Array of TOtherClass; function GetIndxProp(Index: Integer): TOtherClass; procedure Se...
I've got two questions (of which at least one is regarding RTTI in D2010 and dynamic instancing) I was reading what appears to be the foils for a conference talk by Barry Kelly, and found on p. 13 something that looked really interesting: TRTTIConstructor.Invoke. In an adjacent bullet point, one finds "Dynamically construct instances w...
Hi, If I have a superclass, say Animal, and two subclasses: Zebra and Giraffe, If I decide to define a Vector of Animals: Vector <Animal> animals = new Vector(); and I want to say: You can add Giraffes, but you must own at least one Zebra first. What is the best way to do this without using RTTI? (instanceof) ...
I'd like to set the length of a dynamic array, as suggested in this post. I have two classes TMyClass and the related TChildClass defined as TChildClass = class private FField1: string; FField2: string; end; TMyClass = class private FField1: TChildClass; FField2: Array of TChildClass; end; The array augmentation is implem...
I am trying inject into a dll that sends a void ** for one of the parameters. The void ** can contain structs that are created in the application. Is there any way of getting data out of the structs. ...
Based on one answer to an earlier post, I'm investigating the possibility of the following design TChildClass = class(TObject) private FField1: string; FField2: string; end; TMyClass = class(TObject) private FField1: TChildClass; FField2: TObjectList<TChildClass>; end; Now, in the real world, TMyClass will have 10 differe...
I am developing visual game level editor in c++. For this I want reflection(RTTI) mechanism to know class attributes at runtime. I am currently using PDB files for this.But using PDB I couldn't retrieve actual code line for extra information in commented format which is given for that attribute. Visual studio uses NCB files for intellige...
Hi, Can anybody tell me how to activate RTTI in c++ when working on unix. I heard that it can be disabled and enabled. on my unix environment,how could i check whether RTTI is enabled or disabled? I am using the aCC compiler on HPUX. ...
I found great explanation about the new RTTI in Delphi,but I don't understand one important thing about all I have read - Where can I use that? What is it supposed to replace? ...
I am implementing a Boilerplate feature - allow users to Change descriptions of some components - like Tlabels - at run time. e.g. TFooClass = Class ( TBaseClass) Label : Tlabel; ... End; Var FooClass : TFooClass; ... At Design time, the value Label's caption property is say - 'First Name', when the application is run, there ...
This is a bit of an involved problem, so I'll do the best I can to explain what's going on. If I miss something, please tell me so I can clarify. We have a callback system where on one side a module or application provides a "Service" and clients can perform actions with this Service (A very rudimentary IPC, basically). For future refer...