Just upgraded to Lion from SL, and downloaded xCode from app store. 

I go to compile "Hello World" and find that g++ isn't being found. After some searching, I find it in /Developer/usr/bin. I add this to my path, and try to compile, and now its saying it can't find iostream. 

Clearly, I missed some key setup step but I don't seem to know what it is. I don't seem to remember any of this when I installed dev tools for previous mac OS upgrades. Anyone else run into this problem or offer some advice?

The code I'm compling is dirt simple obviously, file name helloworld.cpp

```
#include <iostream>
int main() { std::cout << "Hello World" << std::endl; }

```

Just trying 

```
g++ helloworld.cpp

```

and its saying it can't find iostream.h (no such file or directory)

Thanks for your help.