What does __inline__ mean ?

Question

I am trying to learn C. Reading through some code, I came across a line like this:

__inline__ void () ...

What does the __inline__

Answer 1

The __inline__ declaration tells the compiler that wherever the function will be called to "inline" the function instead. Inlineing is similar to using a macro -- the code will be expanded out as if you had written it all right where you called the function.

See the GNU docs for more information.