Re: [Mingw-users] __CRT_INLINE why with extern ?

[JonY <10...@gm...>]

On 10/13/2008 11:18, Brian Dessent wrote:
> Roumen Petrov wrote:
>
>> If I omit extern from function declaration it is fine.
>
> "extern inline" on a definition tells gcc to use that definition only
> for the purposes of inlining, but never emit and out-of-line copy of the
> function body.  Plain "inline" both emits an out-of-line copy and uses
> the definition for inlining.
>
> Thus when you say "extern inline" what you are saying is "this is a
> version of the function that you should use for any call site where it
> can be inlined, but there is a separate callable library version of the
> function elsewhere."  But if there is no separate library version
> elsewhere then any callsite that couldn't be inlined will fail -- and
> note that gcc does no inlining without optimization enabled (-O), so you
> really can't use "extern inline" alone in a header without a
> corresponding library function somewhere.
>

Also, how gcc handles the {extern,static} inline keywords depends on 
whether it was set to C99 or C89 mode.

More here: <http://gcc.gnu.org/ml/gcc/2006-11/msg00006.html>