title: In g++ is C++ 11 thread model using pthreads in the background?
body: <p>I am just trying my hands on <code>g++ 4.6</code> and <code>C++11</code> features.
  Every time I compile a simple threading code using <code>-std=c++0x</code> flag, either it crashes with segmentation fault or it just throws some weird exception.</p>
  
  <p>I read some questions related to <code>C++11</code> threads and I realized that, I also need to use <code>-pthread</code> flag to compile the code properly. Using <code>-pthread</code> worked fine and I was able to run the threaded code.</p>
  
  <p>My question is, whether the <code>C++11</code> multi-threading model uses <code>Pthreads</code> in the background?
  Or is it written from the scratch?</p>
  
  <p>I don't know if any of the members are <code>gcc</code> contributors but I am just curious. </p>