Is there an online manual of C++ preprocessor directives?

Is there a place where I can learn what all the different preprocessor directives in the C++ standard libraries do? Like a site where it开发者_如何学Python would break down all the different things you could do with math.h, conio.h, etc.?

I'm not sure if you really want to know about preprocessor directives, or about "what you can find in each standard header" (which are two very different things). For both questions, I would recommend getting a good C++ book or looking into online references.

I don't think there's a special section about preprocessor directives only, but the C++ standard defines what each standard include file must supply.

If you prefer to avoid reading the whole standard, you'll find many informations about standard header files on the web, also on Wikipedia.

Note a few things: conio.h is not standard, it's a microsoft extension, you won't find anything about it on the language standard. C++ header files inherited from C lose the suffix ".h" and gain a "c" at the beginning: math.h is cmath. Many C++ native header files are the ones implementing Standard Template Library.