David Heffernan

This is known to be unreliable

type TFoo<T> = class type TSetOfT = set of T; end; The compiler reports this error for me: [dcc32 Error] E2001 Ordinal type required

https://stackoverflow.com/questions/9360280/how-to-make-a-lib-file-when-have-a-dll-file-and-a-header-file

Of course it makes sense. Try declaring set of TObject and see how that works out. You'd need to constrain to an ordinal type with 256 or fewer elements and you can't do that with constraints. Too bad we can't have templates.

Whilst you can't use constraints, you can use generics and RTTI to get some effective code reuse when working with enums and sets. Ideally this could be done truly generically but such is life with Delphi.

We can't see what the class does. You've just shown the interface.

I think the answer is still no.

I cannot understand what you mean by event in component or instance. In fact I can't make any sense out of this.

I can't understand the question at all

If you want to fully test your own app this is the way to go, so that you get top down allocation for all the addresses in your program. You won't necessarily find all the issues if you only do the fastmm local allocator. Using OS top down has always worked well for me.

Better is to use OS level top down allocation.

Nothing here is "as expected". This is all undefined behaviour that is subject to change in future compiler releases. It's a mistake to read the return value before assigning to it.

Delphi strings are managed types so they are never ill-defined in the way that unmanaged types can be before first assignment. Note that this assumes correct practise. So if you use GetMem rather than New to allocate memory for a managed type then the above statement is not correct, but then doing that would be incorrect practise.

Maybe so. But my point about how to deal with getting a pointer from a string that may be zero length stands. So long as the use of the pointer respects the zero length and doesn't try to de-reference it.

The correct solution, in my view, is to pass Pointer(RawMessage) rather than @RawMessage [1]

This can easily happen. It's really common. Programming mistake in the app manifests as an exception raised in vcl code. Nothing interesting to see here.

Here's what to do. First of all you need to understand the R code. You need to know what it's purpose is, and how it achieves it. You will need a clear understanding of what data types are expected to be passed to, and returned from the function. You may need to talk to the author of the code, or learn enough R to work it out yourself. Once you have a clear understanding then you will be in a good place to write an equivalent function in Delphi. Good luck.

If you comment out all of the code then the library will compile. And we all know that once a piece of code compiles, the job of the programmer is done.

Index out of range error. Stack overflow. Invalid operation. Is that how this works?

So make the necessary changes. Or hire a programmer.

I can't make any sense of what you are asking here.

Perhaps the bug is in some other code in the user's program. One of the recurring themes with questions like this is that the asker often doesn't know how to use, or even realise the value, of the debugger. Re-writing the code for them doesn't help them learn that.

Do you understand what the error message tells you? You are using an index i outside the range 0 to Count-1. You can use your debugger to find out which indexing operation is out if bounds. Debugging by looking at code can be quite hard. Delphi has a powerful debugger for such moments.

Do you know this?

The reason I asked for a minimal reproduction is that by making one, and making it minimal, you'd have learnt a good debugging technique. Instead you posted loads of spurious code. But the act of curltting it down to a minimal reproduction would have led you to the error. Then again, the compiler told you which line the error was on and somehow you missed that information.