title: C++ TR1 Regular Expressions Not Available
body: <p>I'm trying to utilize the 'TR1' regular expression extensions for some C++ string parsing. 
  I've read that the <code>&lt;regex&gt;</code> header and namespace std::tr1 are required for this</p>
  
  <p>I can compile with the <code>&lt;regex&gt;</code> header present(though it forces me to use either the flag,     <code>-std=c++0x</code> or <code>-std=gnu++0x</code>)</p>
  
  <p>However, when I attempt to use the <code>std::tr1</code> namespace in my program, compiling fails with message that tr1 "is not a namespace name". I cant do things like, </p>
  
  <p><code>std::tr1::regex rx("mypattern");</code></p>
  
  <p>I've read that TR1 regular expressions have been supported since gcc 4.3.0. I'm using g++ through gcc 4.4.5. </p>
  
  <p>Am I missing something?</p>