> Wouldn't adding a preprocessor directive like "#include_once <header.h>" solve this? Obj-C already has this: #import http://en.wikipedia.org/wiki/Objective-C

> Wouldn't adding a preprocessor directive like "#include_once <header.h>" solve this? Obj-C already has this: #import http://en.wikipedia.org/wiki/Objective-C#.23import http://en.wikipedia.org/wiki/Objective-C#.23import It’s just #include with built-in guards, but headers still have to be compiled once per compilation unit.