title: Xcode - C++ libstdc++ Thread file not found - C++11 enabled
body: <p>I have a program that I need to compile using <code>libstdc++</code> but I am getting a compilation error stating <code>thread file not found</code>. </p>
  
  <p>I have added <code>C++11</code> in the language dialect option for the LLVM compiler but I am still getting the error that the <code>thread file is not found</code>.</p>
  
  <p>Does anything additional need to be added to the linker flags for thread support?</p>