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 Posted: Tue May 08, 2007 9:12 am Post subject: Purpose of #define inside struct definition? |
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Following is a snippet of a header file.
Here, #define are inside struct evConn{}
Any advantage of putting them inside struct block?
Looks like there is no diff in scoping of each identifier between
inside and outside struct block....
typedef struct evConn {
evConnFunc func;
void * uap;
int fd;
int flags;
#define EV_CONN_LISTEN 0x0001 /* Connection is a listener. */
#define EV_CONN_SELECTED 0x0002 /* evSelectFD(conn->file). */
#define EV_CONN_BLOCK 0x0004 /* Listener fd was blocking. */
evFileID file;
struct evConn * prev;
struct evConn * next;
} evConn; |
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Ian Collins
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| Posted: Tue May 08, 2007 9:12 am Post subject: Re: Purpose of #define inside struct definition? |
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djhong (AT) gmail (DOT) com wrote:
| Quote: | Following is a snippet of a header file.
Here, #define are inside struct evConn{}
Any advantage of putting them inside struct block?
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Probably written this way to show the flags are associated with the
flags member of the struct.
| Quote: | Looks like there is no diff in scoping of each identifier between
inside and outside struct block....
typedef struct evConn {
evConnFunc func;
void * uap;
int fd;
int flags;
#define EV_CONN_LISTEN 0x0001 /* Connection is a listener. */
#define EV_CONN_SELECTED 0x0002 /* evSelectFD(conn->file). */
#define EV_CONN_BLOCK 0x0004 /* Listener fd was blocking. */
evFileID file;
struct evConn * prev;
struct evConn * next;
} evConn;
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Ian Collins. |
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Michal Nazarewicz
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| Posted: Wed May 09, 2007 9:11 am Post subject: Re: Purpose of #define inside struct definition? |
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Christopher Benson-Manica <ataru (AT) otaku (DOT) freeshell.org> writes:
| Quote: | Just from a style perspective, I might personally prefer these to be
#define EV_CONN_LISTEN ( 0x0001 << 0 ) /* Connection is a listener. */
#define EV_CONN_SELECTED ( 0x0001 << 1 ) /* evSelectFD(conn->file). */
#define EV_CONN_BLOCK ( 0x0001 << 2 ) /* Listener fd was blocking. */
to clearly indicate that they are bitmask flags, but I imagine this
isn't your code anyway - just a thought. (And to see how silly an
idea others feel this is.)
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Personally, I find this method easier to edit. If I have like 20
masks it's easier to delete one from the middle or rearrange them when
they are written using (1 << n) idiom.
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Best regards, _ _
.o. | Liege of Serenly Enlightened Majesty of o' \,=./ `o
..o | Computer Science, Michal "mina86" Nazarewicz (o o)
ooo +--<mina86*tlen.pl>---<jid:mina86*chrome.pl>--ooO--(_)--Ooo-- |
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