Thanks for all your help,
I have installed xcode which installed g++ and now textmate works. I run into another problem which I have read somewhere though.
Now if I have a program that requests user input with cin >> textmate after a Command-R does not ask for any input from the user...
Any ideas on why that is and how to fix it?
Like Thor said it was removed some time ago. Here is an article on how to put it back, but I can only assume it's even less compatible with Lion. It may be worth a shot though.