title: What versions of gcc, llvm and clang are in XCode 4?
body: <p>For some reason, this information is difficult to come by.</p>
  
  <p>We'd like to start using some of the C++0x features that are available in most compilers.  But we are held back a bit by XCode 3, since it only provides GCC 4.2 and LLVM 1.5.  All of the other platforms we need to support either already have compilers with preliminary support for C++0x features, or they have a relatively painless method of installing/upgrading the compiler.</p>
  
  <p>An XCode 4 preview is available, but only to those in the Mac or iOS Developer Program.</p>