title: C++11 library features dependent on compiler specific proxys
body: <p>It's been brought to my attention by trial and error that there are certian C++11 features that depend on some sort of compiler magic (TM).  I've been messing around with implementing my own standard conformant stdlib.  I know there are readily available implementations of the stdlib, but this one is more of my own personal version for small applications.</p>
  
  <p>Last night I implemented <code>std::initializer_list</code> according to spec, and I was having trouble making it work, I searched high and low for anwers only to be left with statements that it was impossible, and that it would require modifications to the compiler itself.  Well I decided to take a look at the current <code>libstdc++</code> implementation of it, and sure enough my implementation was exactly the same in design, just slightly different around the edges, I wasted pointless hours figuring out why the implementation was not working, when it was exactly the same in design as the one in <code>libstdc++</code>.  It was not untill six hours in before I realised it had to be in namespace std.  Turns out the implementation is merley a proxy to the compiler which makes the <code>initializer_list</code> possible, and the compiler itself searches for the <code>initializer_list</code> class in <code>namespace std</code>.</p>
  
  <p>My question is are there anymore other library features I should be aware of that require some sort of special compiler magic to work, any more hidden proxy connections, or secrete compiler intristics for any of the new C++11 library features?
  I would like to know these in advance so I can be prepared for when I do implement other functionality that depends on <em>compiler magic</em>, instead of wasting a whole day figuring it out by trial and error; which can get tedious and rather annoying.</p>
  
  <p>Thanks.</p>