Error: invalid user-defined conversion from WrappedImage to PFFINALRELEASE (C++)

Programming Questions C++ API
1

I reproduce the exemple in the tutorial of polimago(cookies) but without cvbquick only with the terminal so without a window. But i have a Strange error when i compile and if i use a compile option to ignore this error i can’t load an image . So if someone have an idea to help me thanks.

the error message:

[build] [1/2  50% :: 5.126] Building CXX object CMakeFiles/classeurfinal.dir/main.cpp.obj
[build] FAILED: CMakeFiles/classeurfinal.dir/main.cpp.obj 
[build] C:\msys64\mingw32\bin\g++.exe   -isystem "C:/Program Files (x86)/STEMMER IMAGING/Common Vision Blox/Lib/C" -g -MD -MT CMakeFiles/classeurfinal.dir/main.cpp.obj -MF CMakeFiles\classeurfinal.dir\main.cpp.obj.d -o CMakeFiles/classeurfinal.dir/main.cpp.obj -c ../main.cpp
[build] In file included from C:/Program Files (x86)/STEMMER IMAGING/Common Vision Blox/Lib/C/cvb/_decl/decl_vpat.hpp:6,
[build]                  from C:/Program Files (x86)/STEMMER IMAGING/Common Vision Blox/Lib/C/cvb/image.hpp:3,
[build]                  from ../main.hpp:5,
[build]                  from ../main.cpp:1:
[build] C:/Program Files (x86)/STEMMER IMAGING/Common Vision Blox/Lib/C/cvb/_cexports/c_img.h: In instantiation of 'Cvb::V_1_4::CExports::cvbres_t Cvb::V_1_4::CExports::__CreateImageFromPointer(ARGS&& ...) [with ARGS = {void*&, unsigned int, long int, long int, long int, long int, int, int, int, long int*, Cvb::V_1_4::WrappedImage::Create(void*, int, int, int, int, Cvb::V_1_4::DataType, int, int, int, int*)::<lambda(void*&)>::<lambda(void*, void*)>, std::nullptr_t, void*&}; Cvb::V_1_4::CExports::cvbres_t = long int]':
[build] C:/Program Files (x86)/STEMMER IMAGING/Common Vision Blox/Lib/C/cvb/_decl/decl_wrapped_image.hpp:140:16:   required from here
[build] C:/Program Files (x86)/STEMMER IMAGING/Common Vision Blox/Lib/C/cvb/_cexports/c_img.h:366:1: error: invalid user-defined conversion from 'Cvb::V_1_4::WrappedImage::Create(void*, int, int, int, int, Cvb::V_1_4::DataType, int, int, int, int*)::<lambda(void*&)>::<lambda(void*, void*)>' to 'Cvb::V_1_4::CExports::PFFINALRELEASE' {aka 'void (__attribute__((stdcall)) *)(void*, void*)'} [-fpermissive]
[build]   366 | CVB_DEF_CAPI_X(cvbres_t, CreateImageFromPointer, (void * pImageMem, std::size_t MemSize, cvbdim_t Width, cvbdim_t Height, cvbdim_t NumPlanes, cvbdatatype_t DataType, std::intptr_t PitchX, std::intptr_t PitchY, std::intptr_t PitchPlane, cvbval_t PlaneOrder[], PFFINALRELEASE ReleaseCallback, void * pUserData, IMG & ImgOut))
[build]       | ^~~~~~~~~~~~~~
[build] C:/Program Files (x86)/STEMMER IMAGING/Common Vision Blox/Lib/C/cvb/_decl/decl_wrapped_image.hpp:140:16: note: candidate is: 'Cvb::V_1_4::WrappedImage::Create(void*, int, int, int, int, Cvb::V_1_4::DataType, int, int, int, int*)::<lambda(void*&)>::<lambda(void*, void*)>::operator void (*)(void*, void*)() const' <near match>
[build]   140 |         return CVB_CALL_CAPI(CreateImageFromPointer(buffer,
[build]       |                ^~~~~~~~~~~~~
[build] C:/Program Files (x86)/STEMMER IMAGING/Common Vision Blox/Lib/C/cvb/_decl/decl_wrapped_image.hpp:140:16: note:   no known conversion from 'void (*)(void*, void*)' to 'Cvb::V_1_4::CExports::PFFINALRELEASE' {aka 'void (__attribute__((stdcall)) *)(void*, void*)'}
[build] C:/Program Files (x86)/STEMMER IMAGING/Common Vision Blox/Lib/C/cvb/_cexports/c_img.h:366:1: note:   initializing argument 11 of 'Cvb::V_1_4::CExports::cvbres_t Cvb::V_1_4::CExports::CreateImageFromPointer(void*, std::size_t, Cvb::V_1_4::CExports::cvbdim_t, Cvb::V_1_4::CExports::cvbdim_t, Cvb::V_1_4::CExports::cvbdim_t, Cvb::V_1_4::CExports::cvbdatatype_t, intptr_t, intptr_t, intptr_t, Cvb::V_1_4::CExports::cvbval_t*, Cvb::V_1_4::CExports::PFFINALRELEASE, void*, void*&)'
[build]   366 | CVB_DEF_CAPI_X(cvbres_t, CreateImageFromPointer, (void * pImageMem, std::size_t MemSize, cvbdim_t Width, cvbdim_t Height, cvbdim_t NumPlanes, cvbdatatype_t DataType, std::intptr_t PitchX, std::intptr_t PitchY, std::intptr_t PitchPlane, cvbval_t PlaneOrder[], PFFINALRELEASE ReleaseCallback, void * pUserData, IMG & ImgOut))
[build]       | ^~~~~~~~~~~~~~
[build] ninja: build stopped: subcommand failed.
[build] La build s'est achevée avec le code de sortie 1
2

It seems the image is converted improperly. Could you please share the code? Also I would recommend using cmake.

1 Like
3

i use cmake and with the option fpermissive it work.but thank you for your help

4

Hi @enzo,

please be aware, that we do not support mingw.
Anyway you probably run into a special issue here as using a lamda as C function pointer is not well defined, especially with calling conventions. On our supported platforms and compilers it works.

However, here the complain/error seems valid. If it works ignoring it you may continue this way.

5

As we’re talking about the release callback here, the effect will only show at runtime (once the image goes out of scope and :cvb: invokes the lambda). So I recommend to test that bit early on…