How is this useful ???

[hotadvice]

hi all

I was just browsing some code(actually apache)

and i found this :

typedef struct apr_pool_t apr_pool_t

How this is usefull??


Thanx in advance

Aman Aggarwal

[Richard Bos]

Re: How is this useful ???

"hotadvice" <aman.coe@gmail .com> wrote:
[color=blue]
> typedef struct apr_pool_t apr_pool_t
>
> How this is usefull??[/color]

Erm... it defines a type alias for a struct type? How else would it be
useful? It means that instead of referring to that type as struct
apr_pool_t, you can now do so using just apr_pool_t. Saves a whole
whopping seven characters. Personally, I never bother unless I want to
hide the underlying type, but there are those who prefer this.

Richard

[Zara]

Re: How is this useful ???

On 28 Oct 2005 04:57:16 -0700, "hotadvice" <aman.coe@gmail .com> wrote:
[color=blue]
>hi all
>
>I was just browsing some code(actually apache)
>
>and i found this :
>
>typedef struct apr_pool_t apr_pool_t
>
>How this is usefull??
>
>
>Thanx in advance
>
>Aman Aggarwal[/color]

I'll be whipped for mentioning it, butusing this typedef you can write
the rest of the references to this struct in a way compatible both to
C and C++.

Please, do not beat me too much for naing Satan in tthis Temple... ;-)

[Martin Ambuhl]

Re: How is this useful ???

hotadvice wrote:
[color=blue]
> I was just browsing some code(actually apache)
> and i found this :[/color]
[color=blue]
> typedef struct apr_pool_t apr_pool_t[/color]
[color=blue]
> How this is usefull??[/color]

(Not at all without the missing semicolon.)
It saves typing the characters 'struct ' in declarations of 'struct
apr_pool_t' objects. If avoiding typing a few characters seems useful
to you, then the typedef begins to be useful if you use this type more
than 5 times (since typing the typedef itself must be offset).

[Dave Thompson]

Re: How is this useful ???

On Fri, 28 Oct 2005 13:27:34 GMT, Zara <yozara@terra.e s> wrote:
[color=blue]
> On 28 Oct 2005 04:57:16 -0700, "hotadvice" <aman.coe@gmail .com> wrote:[/color]
[color=blue][color=green]
> >typedef struct apr_pool_t apr_pool_t[/color][/color]
[color=blue]
> I'll be whipped for mentioning it, butusing this typedef you can write
> the rest of the references to this struct in a way compatible both to
> C and C++.
>[/color]
Compatible with the usual and arguably preferred C++ style.

C++ does (also) allow you to use the C-like form, which it calls an
elaborated-type-specifier -- struct foo, class foo, union foo, or enum
foo -- as well as just foo. And in name conflict cases that are
arguably bad style anyway it requires it, as C always does.
- David.Thompson1 at worldnet.att.ne t