> Hi, All.
>
> I found there are use double operator ! continuously sometimes in
> kernel.
> e.g:
>
> static inline int is_page_cache_freeable(struct page *page)
> {
> return page_count(page) - !!PagePrivate(page) == 2;
> }
>
> Who would like tell me why write like above?
>
>
> Thanks in advanced.
>
>
> Liyu
For example,
int test = 5;
!test will be 0, !!test will be 1.
This give a enum of {0,1}. If test is not 0, !!test will give 1, otherwise 0.
Am I right?
--
RomanU
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