rtti

问题 how to extract RTTI info about methods in Delphi records? is it possible by using new Rtti unit? 回答1: There is no RTTI for methods on records, sorry. 来源： https://stackoverflow.com/questions/2489230/delphi-rtti-info-about-methods-in-records

问题 Is it meant to be guaranteed that same std::type_info::hash_code() values imply same types? Cplusplus.com seems to claim so: This function returns the same value for any two type_info objects that compare equal, and different values for distinct types that do not. [Emphasis mine] Cppreference seems to claim otherwise: Returns an unspecified value, which is identical for objects, referring to the same type. No other guarantees are given , in particular, the value can change between invocations

问题 Does anyone know of a TDataset descendant that works with Generics and RTTI, so that I can write code like this, and make use of data-aware components in the GUI? : ... ds:TDataset<TPerson>; ... procedure DoStuff; begin ds:=TDataset<TPerson>.create; ds.add(TPerson.Create('A.','Hitler',77)); ds.add(TPerson.Create('O.','Bin Laden',88)); end; This should be possible. The fielddefs can be created via RTTI because the exact type of the data is known. Values can also be automatically marshalled

问题 I want to duplicate a class. It is sufficient that I copy all properties of that class. Is it possible to: loop thru all properties of a class? assign each property to the other property, like a.prop := b.prop ? The getters and setters should take care of the underlying implementation details. EDIT: As Francois pointed out I did not word my question carefully enough. I hope the new wording of the question is better SOLUTION: Linas got the right solution. Find a small demo program below.

问题 I have class B that inherits from A. class A { }; class B : public A { }; And I have three objects. A* a = new A(); A* a2 = new B(); B* b = new B(); I'd like to if check a is object of type A, a2 is object of type B (not A), and b is object of type B. I tried typed comparison, but it doesn't give me correct answer. cout << (typeid(*a) == typeid(A)) << endl; // -> 1 cout << (typeid(*a2) == typeid(A)) << endl; // -> 1 cout << (typeid(*b) == typeid(A)) << endl; // -> 0 cout << (typeid(*a) ==

问题 Is there at way, at runtime, to find all classes that descend from a particular base class? For example, pretend there is a class: TLocalization = class(TObject) ... public function GetLanguageName: string; end; or pretend there is a class: TTestCase = class(TObject) ... public procedure Run; virtual; end; or pretend there is a class: TPlugIn = class(TObject) ... public procedure Execute; virtual; end; or pretend there is a class: TTheClassImInterestedIn = class(TObject) ... public procedure

问题 I suspect that I am not quite grokking Swift 1.2, and I need to RTFM a bit more. I'm working on a Swift app that reads JSON data from a URI. If the JSON data is bad, or nonexistent, no issue. The JSON object never instantiates. However, if the JSON data is good JSON, but not what I want, the object instantiates, but contains a structure that is not what I'm looking for, I get a runtime error. I looked at using Swift's "RTTI" (dynamicType), but that always returns "<Swift.AnyObject>", no

问题 Preface, it seems i failed to say it clear. I want to enumerate, read and set, all the class var or class properties of a given TClass variable. There is no problem in finding TClass - it is passed. There is no problem in filtering by presence of given attribute. There problem is that RTTI just misses the way to enumerate class fields rather than instance fields. I wanted to make a declarative DLL Loader. Since the DLLs are process-global in windows (you cannot load the same DLL twice) it

问题 I am working with Delphi application.I created one form shown as below: I wanted to make component out of this controls through code . But not through component-->create component Template -->so on. How do i make component template out of form contols through delphi code .?? Thanx in advance. 回答1: Or if you want to have that group of controls as one single component you can install unit like this into some package: unit EditGroup; interface uses SysUtils, Classes, Graphics, Controls, StdCtrls

问题 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 about the use of the word "polymorphic", here's the entry in cplusplus.com that prompted me to ask this: dynamic_cast can be used only with pointers and