rtti

consider this simple code {$APPTYPE CONSOLE} uses Rtti, SysUtils; type {$M+} TFoo = class strict private class var Field1 : Integer; field2 : Integer; private field3 : Integer; class var Field4 : Integer; end; Var ctx : TRttiContext; f : TRttiField; begin try ctx:=TRttiContext.Create; for f in ctx.GetType(TFoo).GetFields do Writeln(f.Name); Writeln('Done'); readln; except on E: Exception do Writeln(E.ClassName, ': ', E.Message); end; end. When you run this, only the field3 is listed. it seems which the RTTI does not support fields which are strict private or class var , So the questions are Is

for a framework I wrote a wrapper which takes any object, interface or record type to explore its properties or fields. The class declaration is as follows: TWrapper<T> = class private FType : TRttiType; FInstance : Pointer; {...} public constructor Create (var Data : T); end; In the constructor I try to get the type information for further processing steps. constructor TWrapper<T>.Create (var Data : T); begin FType := RttiCtx.GetType (TypeInfo (T)); if FType.TypeKind = tkClass then FInstance := TObject (Data) else if FType.TypeKind = tkRecord then FInstance := @Data else if FType.TypeKind =

Everything I've read indicates that TRTTIContext is thread-safe. However, TRTTIContext.FindType seems to fail (returns nil) occasionally when multithreading. Using a TCriticalSection around it fixes the issue. Note that I'm using XE6, and the issue doesn't seem to exist in XE. Edit: Seems to exist in all Delphi editions that have the new RTTI units. I've worked up a test project you can use to see for yourself. Create a new VCL project, drop a TMemo and a TButton, replace unit1 with below, and assign the Form1.OnCreate, Form1.OnDestroy and Button1.OnClick events. The key CS is the GRTTIBlock

According to cplusplus.com, the std::type_info::before() function... Returns true if the type precedes the type of rhs in the collation order. The collation order is just an internal order kept by a particular implementation and is not necessarily related to inheritance relations or declaring order. So what is it useful for? Consider you want to put your type_info objects as keys into a map<type_info*, value> . The type_info doesn't have an operator < defined, so you must provide your own comparator. The only thing that is guaranteed to work from the type_info interface is the before()

I've stored a pointer to a type_info object. int MyVariable = 123; const std::type_info* Datatype = &typeid(MyVariable); How might I use this to typecast another variable to that type? I tried this, but it doesn't work: std::cout << ((*Datatype)3.14) << std::endl; Using the function form of typecasting doesn't work, either: std::cout << (*Datatype(3.14)) << std::endl; Mark B I don't think such casting can be done. Suppose you could do "dynamic" casting like this at runtime (not to mean dynamic_cast ). Then if you used the result of the cast to call a function the compiler could no longer do