title: Errors in cstdint: No member named xxx in global namespace
body: <p>What can cause errors like these? I added an empty project to Xcode, added /usr/local/lib  in the Header Search Paths, and added some opencv libraries. Building gave these errors:</p>
  
  <p><img src="https://i.stack.imgur.com/XQ5Dq.png" alt=""></p>
  
  <p><strong>UPDATE</strong></p>
  
  <p>It appears stdint.h is indeed installed on my system. I'm running on OS 10.9, so types like <code>int_least16_t</code> that xcode can't find in the global namespace do appear to be defined.</p>
  
  <p><code>typedef int16_t         int_least16_t;</code>.</p>
  
  <pre><code>find /Applications/Xcode.app -name stdint.h
  /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.1.sdk/usr/include/c++/4.2.1/tr1/stdint.h
  /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.1.sdk/usr/include/stdint.h
  /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator7.1.sdk/usr/include/c++/4.2.1/tr1/stdint.h
  /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator7.1.sdk/usr/include/stdint.h
  /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk/System/Library/Frameworks/Kernel.framework/Versions/A/Headers/stdint.h
  /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk/usr/include/c++/4.2.1/tr1/stdint.h
  /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk/usr/include/stdint.h
  /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/System/Library/Frameworks/Kernel.framework/Versions/A/Headers/stdint.h
  /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/include/c++/4.2.1/tr1/stdint.h
  /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/include/stdint.h
  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/5.1/include/stdint.h
  </code></pre>