title: Compiler errors after upgrading to Opencv 2.4.5 on iOS. Is there a quick fix to these issues?
body: <p>After upgrading the openCV version on an existing iOS project, I get the following problems.
  I have tried playing around with compiler version and some other settings but I haven't found a solution.</p>
  
  <p>Thanks.</p>
  
  <pre><code>Ld /Users/_____/Library/Developer/Xcode/DerivedData/_____-czzcfkvvtejzzacaookbbwcmfsdh/Build/Products/Debug-iphoneos/_____.app/_____ normal armv7
  cd /Users/________/Desktop/________NewOpenCV
  setenv IPHONEOS_DEPLOYMENT_TARGET 5.0
  setenv PATH "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -arch armv7 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.1.sdk -L/Users/_____/Library/Developer/Xcode/DerivedData/________-czzcfkvvtejzzacaookbbwcmfsdh/Build/Products/Debug-iphoneos -L/Users/________/Desktop/________NewOpenCV/../../Downloads/opencv2.framework/Versions/A -F/Users/________/Library/Developer/Xcode/DerivedData/________-czzcfkvvtejzzacaookbbwcmfsdh/Build/Products/Debug-iphoneos -F/Users/________/Desktop/________NewOpenCV -F/Users/________/Desktop/________NewOpenCV/../../Downloads/aptogo-OpenCVForiPhone-cb262eb -F/Users/________/Desktop/________NewOpenCV/../../Downloads -filelist /Users/________/Library/Developer/Xcode/DerivedData/________-czzcfkvvtejzzacaookbbwcmfsdh/Build/Intermediates/________.build/Debug-iphoneos/________.build/Objects-normal/armv7/________.LinkFileList -dead_strip -fobjc-arc -fobjc-link-runtime -miphoneos-version-min=5.0 /Users/________/Desktop/________NewOpenCV/../../Downloads/opencv2.framework/Versions/A/opencv2 -framework CoreMotion -framework AudioToolbox -framework CoreLocation -lz.1.2.5 -framework ExternalAccessory -framework CFNetwork -framework SystemConfiguration -framework MobileCoreServices -framework AVFoundation -framework UIKit -framework Foundation -framework CoreGraphics -o /Users/________/Library/Developer/Xcode/DerivedData/________-czzcfkvvtejzzacaookbbwcmfsdh/Build/Products/Debug-iphoneos/________.app/________
  
  Undefined symbols for architecture armv7:
  "std::__1::basic_string&lt;char, std::__1::char_traits&lt;char&gt;, std::__1::allocator&lt;char&gt; &gt;::basic_string(std::__1::basic_string&lt;char, std::__1::char_traits&lt;char&gt;, std::__1::allocator&lt;char&gt; &gt; const&amp;)", referenced from:
    cv::Exception::Exception(int, std::__1::basic_string&lt;char, std::__1::char_traits&lt;char&gt;, std::__1::allocator&lt;char&gt; &gt; const&amp;, std::__1::basic_string&lt;char, std::__1::char_traits&lt;char&gt;, std::__1::allocator&lt;char&gt; &gt; const&amp;, std::__1::basic_string&lt;char, std::__1::char_traits&lt;char&gt;, std::__1::allocator&lt;char&gt; &gt; const&amp;, int) in opencv2(system.o)
    cv::error(cv::Exception const&amp;) in opencv2(system.o)
    _cvRegisterModule in opencv2(system.o)
  "std::__1::basic_string&lt;char, std::__1::char_traits&lt;char&gt;, std::__1::allocator&lt;char&gt; &gt;::operator=(std::__1::basic_string&lt;char, std::__1::char_traits&lt;char&gt;, std::__1::allocator&lt;char&gt; &gt; const&amp;)", referenced from:
    cv::Exception::formatMessage() in opencv2(system.o)
  "std::__1::basic_string&lt;char, std::__1::char_traits&lt;char&gt;, std::__1::allocator&lt;char&gt; &gt;::__init(char const*, unsigned long)", referenced from:
    cv::medianBlur(cv::_InputArray const&amp;, cv::_OutputArray const&amp;, int) in opencv2(smooth.o)
    cv::Mat::create(int, int const*, int) in opencv2(matrix.o)
    cv::setSize(cv::Mat&amp;, int, int const*, unsigned long const*, bool) in opencv2(matrix.o)
    cv::Mat::Mat(cv::Mat const&amp;, cv::Range const&amp;, cv::Range const&amp;) in opencv2(matrix.o)
    cv::Mat::Mat(cv::Mat const&amp;, cv::Range const*) in opencv2(matrix.o)
    cv::Mat::diag(int) const in opencv2(matrix.o)
    cv::Mat::Mat(_IplImage const*, bool) in opencv2(matrix.o)
    ...
   "std::__1::basic_string&lt;char, std::__1::char_traits&lt;char&gt;, std::__1::allocator&lt;char&gt; &gt;::~basic_string()", referenced from:
    cv::medianBlur(cv::_InputArray const&amp;, cv::_OutputArray const&amp;, int) in opencv2(smooth.o)
    cv::Mat::create(int, int const*, int) in opencv2(matrix.o)
    cv::setSize(cv::Mat&amp;, int, int const*, unsigned long const*, bool) in opencv2(matrix.o)
    cv::Mat::Mat(cv::Mat const&amp;, cv::Range const&amp;, cv::Range const&amp;) in opencv2(matrix.o)
    cv::Mat::Mat(cv::Mat const&amp;, cv::Range const*) in opencv2(matrix.o)
    cv::Mat::diag(int) const in opencv2(matrix.o)
    cv::Mat::Mat(_IplImage const*, bool) in opencv2(matrix.o)
    ...
   "std::__1::__vector_base_common&lt;true&gt;::__throw_length_error() const", referenced from:
    cv::medianBlur(cv::_InputArray const&amp;, cv::_OutputArray const&amp;, int) in opencv2(smooth.o)
    std::__1::vector&lt;int, std::__1::allocator&lt;int&gt; &gt;::__append(unsigned long) in opencv2(smooth.o)
    std::__1::vector&lt;cv::Vec&lt;int, 128&gt;, std::__1::allocator&lt;cv::Vec&lt;int, 128&gt; &gt; &gt;::__append(unsigned long) in opencv2(matrix.o)
    std::__1::vector&lt;cv::Vec&lt;int, 64&gt;, std::__1::allocator&lt;cv::Vec&lt;int, 64&gt; &gt; &gt;::__append(unsigned long) in opencv2(matrix.o)
    std::__1::vector&lt;cv::Vec&lt;int, 32&gt;, std::__1::allocator&lt;cv::Vec&lt;int, 32&gt; &gt; &gt;::__append(unsigned long) in opencv2(matrix.o)
    std::__1::vector&lt;cv::Vec&lt;int, 16&gt;, std::__1::allocator&lt;cv::Vec&lt;int, 16&gt; &gt; &gt;::__append(unsigned long) in opencv2(matrix.o)
    std::__1::vector&lt;cv::Vec&lt;int, 12&gt;, std::__1::allocator&lt;cv::Vec&lt;int, 12&gt; &gt; &gt;::__append(unsigned long) in opencv2(matrix.o)
    ...
  "cv::split(cv::Mat const&amp;, std::vector&lt;cv::Mat, std::allocator&lt;cv::Mat&gt; &gt;&amp;)", referenced from:
    GetRegionContoursLDC(cv::Mat&amp;, double, double, double, double, int, std::vector&lt;std::vector&lt;cv::Point_&lt;int&gt;, std::allocator&lt;cv::Point_&lt;int&gt; &gt; &gt;, std::allocator&lt;std::vector&lt;cv::Point_&lt;int&gt;, std::allocator&lt;cv::Point_&lt;int&gt; &gt; &gt; &gt; &gt;&amp;) in GetRegionContoursLDC.o
  "cv::putText(cv::Mat&amp;, std::string const&amp;, cv::Point_&lt;int&gt;, int, double, cv::Scalar_&lt;double&gt;, int, int, bool)", referenced from:
    -[NotesUploaderViewController addMotionDetails:] in NotesUploaderViewController.o
    -[NotesUploaderViewController addArea:atPoint:onto:] in NotesUploaderViewController.o
    -[NotesUploaderViewController addMeasureLine:toPoint:usingScale:onto:] in NotesUploaderViewController.o
  ld: symbol(s) not found for architecture armv7
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  </code></pre>