Preprocessor Wrapper?

[BarringtonT]

i read somewhere that a prepocessor wrapper prevent a code in the header file from being include into the same source code file more than once. my question is what the heck does it look like?

[S G H]

http://www.cplusplus.com/forum/articles/10627/#msg49679
It's the

#ifndef ...
#define ...
/*code*/
#endif 

part