In the process of adding boost 1.5.1 to my ios project, I encountered an incompatibility due to C++ Standard Library conflicts, e.g.:

Undefined symbols for architecture armv7:  "std::__1::locale::use_facet(std::__1::locale::id&) const"

since my boost build via galbraithjosephs-boostoniphone compiles with the following options:

-DBOOST_AC_USE_PTHREADS -DBOOST_SP_USE_PTHREADS -std=c++11 -stdlib=libc++

and it appears that the OpenCV 2.4.9 CMake build compiles with gnu++11 and libstdc++. I'm compiling an OpenCV framework with the included build script as follows:

python2.7 opencv/ios/build_framework.py ios

At this point my plan is to try to rebuild my OpenCV framework with the c++11 compiler and libc++ standard library as in the boost build, and then update all of my XCode libraries and applications appropriately.

The following link aimed at OpenCV 2.4.2 OpenCV with C++11 on OS X 10.8 seems to be a good starting point, and it essentially suggests modifying CMakeLists.txt with the following entries:

 message("Setting up Xcode for C++11 with libc++.")
 set(CMAKE_XCODE_ATTRIBUTE_CLANG_CXX_LANGUAGE_STANDARD "c++0x")
 set(CMAKE_XCODE_ATTRIBUTE_CLANG_CXX_LIBRARY "libc++")

but after modifying the opencv/CMakeLists.txt file in the first step my build fails with the following message:

/Volumes/ramdisk/opencv/modules/core/src/arithm.cpp:444:51: error: constant expression evaluates to 4294967295 which cannot be narrowed to type 'int' [-Wc++11-narrowing]
static int CV_DECL_ALIGNED(16) v64f_absmask[] = { 0xffffffff, 0x7fffffff, 0xffffffff, 0x7fffffff };

and I noticed that the output indicates that it is still using the GNU compiler. I see the message added above in the build output

Setting up Xcode for C++11 with libc++.

but the compiler and arguments are still listed as:

-- General configuration for OpenCV 2.4.9 =====================================
-- 
--   Platform:
--     Host:                        Darwin 12.0.0 i386
--     Target:                      iOS
--     CMake:                       2.8.9
--     CMake generator:             Xcode
--     CMake build tool:            /opt/local/bin/cmakexbuild
--     Xcode:                       4.4.1
-- 
--   C/C++:
--     Built as dynamic libs?:      NO
--     C++ Compiler:                /usr/bin/g++
--     C++ flags (Release):         -headerpad_max_install_names -fvisibility=hidden -fvisibility-inlines-hidden   -Wno-c++11-narrowing -DNDEBUG -O3 -fomit-frame-pointer -ffast-math 
--     C++ flags (Debug):           -headerpad_max_install_names -fvisibility=hidden -fvisibility-inlines-hidden   -Wno-c++11-narrowing  
--     C Compiler:                  /usr/bin/gcc
--     C flags (Release):           
--     C flags (Debug):             
--     Linker flags (Release):      
--     Linker flags (Debug):        
--     Precompiled headers:         NO
--

If anyone has advice or a link for how to tune CMake accordingly it would be much appreciated. I would imagine opencv + boost are fairly common siblings for ios platforms.

EDIT: The build also reports a second error

/Volumes/ramdisk/opencv/modules/core/include/opencv2/core/operations.hpp:65:16: fatal error: 'ext/atomicity.h' file not found
      #include <ext/atomicity.h>