   [C++] #ifndef header guards against #pragma once?
  Hi.I've always done my header guards in the format:#ifndef CLASS_H#define CLASS_H#endifBut I know you can also do:#pragma once//stuffIs there any real advantage to one or the other? I thought #pragma wasn't supported on GCC, but apparently it is now. Also, the visual studio class wizard makes header files with #pragma once, and I thought that doing it that way could save time.Thanks.   
  Maybe this will explain some things.   ;  #pragma once is compiler specific and therefore non-standard; not all will recognize it. VC++ for example does.   