How to create IPP (Intel Performace primitives) C++ wrapper functions?

Question

IPP is a C library, with hundreds of functions like this:

IppStatus ippiTranspose_8u_C1R(const Ipp8u* pSrc, int srcStep,
                               Ipp8u* pDst, int dstStep,
                               IppiSize roiSize));

To be able to call these functions in a more convenient, safe and consistent way, we need a C++ wrapper function for each C function. For example:

void ippiTranspose(const Image<Ipp8u> &src, Rect srcRect, Image<Ipp8u> &dst, Point dstPos)
{
  if (!src.valid()) throw "Invalid src";
  if (!dst.valid()) throw "Invalid dst";
  Rect srcRoi = srcRect.isEmpty() ? src.rect() : srcRect;
  if (!src.rect().contains(srcRoi)) throw "Invalid src rect";
  Rect dstRoi = Rect(dstPos, srcRoi.size());
  if (!dst.rect().contains(dstRoi)) throw "Invalid dst rect";
  IppStatus st = ippiTranspose_8u_C1R(&src.at(srcRoi.topLeft()), src.step(), &dst.at(dstRoi.topLeft()), dst.step(), toIppiSize(srcRoi.size());
  if (st < 0) throw "ippiTranspose_8u_C1R failed";
}

There are logical patterns, which can be applied to all the functions in IPP.

How to automatically generate all these wrappers?

Answer 1

Look at the examples there is ippi.hpp file in "language" examples section. It is C++ wrapper.

Answer 2

There are some kind of wrappers, provided by Intel, which are well hidden in ipp-samples for windows only. I'm using the latest 7.0 beta version. They provide C++ headers, generated by a perl script, which are supposed to be used as a C++ wrappers. The "wrapper" for the ippiTranspose_8u_C1R function in the question is this:

 static inline IppStatus ippiTranspose_C1R( const Ipp8u* pSrc, int srcStep, Ipp8u* pDst, int dstStep, IppiSize roiSize) {
   return ippiTranspose_8u_C1R( pSrc, srcStep, pDst, dstStep, roiSize );
 }

This is just a shorter version of the function call.

What I expect from a good C++ wrapper for a C function:

• map C-like params to C++ (objects, templates)
• check if the input params are valid
• check if the result is a success, error or warning
• error handling using exceptions

We need a real solution for the C++ world, Intel!

I am currently working on a program, which automatically generates wrappers like the example in the question, and the things look nice.

Thanks to Ross for pointing the solution from Intel.