Re: [fpc-pascal] How to call C++ function with Vector

2017-09-26 Thread leledumbo via fpc-pascal 
> Would it be possible to do this via a Lua shim?

How is it even related with that?



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Re: [fpc-pascal] How to call C++ function with Vector

2017-09-26 Thread Dennis Poon 



Marco van de Voort wrote:


I myself generally solve this with a wrapper DLL, by crafting a DLL in C++
that exports a C (not C++) interface, and then use that. The same method as
QT is used from Lazarus (via wrapper dll/.so qtpas)
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Thanks.  I think I will follow your advice.

Dennis

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Re: [fpc-pascal] How to call C++ function with Vector

2017-09-26 Thread Marco van de Voort 
In our previous episode, Dennis said:
> I have a windows 32-bit dll written in C++ (probably C++ Builder).
> It has 1 function which I need to call:
> 
> int SPAPI_GetProduct(vector& apiProdList)
> 
> I am stuck at the keyword vector.

It is not a keyword it is a generic type. So that is not easy, specially
since C++ and Pascal classes differ.

And even if the call succeeds, getting results from apiprodlist is major
problem number two.

You can try to match the C++ code with carefully crafted pascal code, but
that requires knowledge about implementation details of the C++
implementaton.

I avoided that way (as too complicated and too fragile), but Rudy Velthuis
has an article on it (C++ <-> Delphi)
http://www.rvelthuis.de/articles/articles-cppobjs.html

I myself generally solve this with a wrapper DLL, by crafting a DLL in C++
that exports a C (not C++) interface, and then use that. The same method as
QT is used from Lazarus (via wrapper dll/.so qtpas)
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Re: [fpc-pascal] How to call C++ function with Vector

2017-09-26 Thread leledumbo via fpc-pascal 
> I am stuck at the keyword vector. 
>
> How is it translated into free pascal?

It's hard, you must create additional wrapper that exposes simpler type
(pointer or array of pchar) OR make wrapper for the vector methods and
simply declare it as an opaque pointer. std::vector is template/generic C++
class that implements a dynamic array functionality, but it can't be used
outside C++.



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