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I have setup OpenCV2 in XCode but unfortunately imshow does not work:

Undefined symbols for architecture x86_64:
  "cv::imshow(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, cv::_InputArray const&)", referenced from:
      _main in main.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I am running OS X 10.8.4 with latest XCode.

I have attached a few images below to show the setup in XCode and the libraries. So far it seems that other functions work fine with OpenCV, except this.

enter image description here

enter image description here enter image description here

JavaCake
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  • I solved this problem with reinstalling opencv, see this [post][1]: [1]: http://stackoverflow.com/a/22955769/457687 – Vlad Apr 09 '14 at 07:38

1 Answers1

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I'm going to go out on a limb and say that you compiled OpenCV2 with libstdc++, and are now compiling your application with libc++ support.

You need to compile OpenCV2 with the same C++ library, otherwise it will not be able to link.

if you do an nm of the OpenCV2 library, if it was compiled with libstdc++, it will look like:

cv::imshow(std::string const&, cv::_InputArray const&)

while if it was compiled with libc++, it would look like:

cv::imshow(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, cv::_InputArray const&)

to get the demangled symbol do:

nm library | c++filt | grep cv::imshow
Anya Shenanigans
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  • Unfortunately i think you are right. This will kill my initialization of `std::vector` which is quite unfortunate.. `No matching constructor for initialization of 'std::vector'` – JavaCake Oct 01 '13 at 15:26
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    Unfortunately, you *have* to compile everything using the same c++ standard library, otherwise insanity could occur at run-time. The namespaces have been doctored to prevent you accidentally doing this (note the `::__1::` in the libc++ compiled option). – Anya Shenanigans Oct 01 '13 at 15:32