macOS cant find iostream

[macmee]

I can #include <iostream> in a c++ command line source in xcode, but I downloaded gtk+ from sourceforge and it can't find iostream, string, or any header files besides the gtk/gtk one. I left clicked the frameworks folder in the left of the project in xcode and added system.framework and IOSurface.framework and still they can't be included. I'm not sure what I'm doing wrong .

 

[jared_kipe]

In xcode you can hold option while you double click the <iostream> and there is a link that says, "Click here to view symbol declaration."

Not sure that helps, I've NEVER programmed in C++.