Regarding typedef

[Oskars Salnins]

Hi
What does the statement:

typedef unsigned my_type_name;

mean? Cannot find an answer to this in ordinary books on C.

--
Thanks,
Osk

[lndresnick@gmail.com]

Re: Regarding typedef

Oskars Salnins wrote:[color=blue]
> Hi
> What does the statement:
>
> typedef unsigned my_type_name;
>
> mean? Cannot find an answer to this in ordinary books on C.
>
> --
> Thanks,
> Osk[/color]

It creates a new name for the unsigned int data type. You could then
use
it in place of a type, e.g.
my_type_name i = 0;

is the now the same as
unsigned i = 0;
or
unsigned int i = 0;

I assume you were confused by the fact that "int" to be inferred? That
is a bit odd, but that is how it works. You can likewise say "signed
short" meaning
"signed short int".

-David

[Martin Ambuhl]

Re: Regarding typedef

Oskars Salnins wrote:[color=blue]
> Hi
> What does the statement:
>
> typedef unsigned my_type_name;
>
> mean? Cannot find an answer to this in ordinary books on C.[/color]

It means that 'my_type_name' is now a synonym for 'unsigned int'.
'unsigned' here is short for 'unsigned int'.

[Angrez Singh]

Re: Regarding typedef

Hi,

It means that you have given a new name to old unsigned data type.
So you can use it instead of unsigned.

For e.g.:
typedef unsigned my_unsigned;

my_unsigned x = 0;

now x will be of type unsigned.

Regards,
Angrez

[vijoeyz@gmail.com]

Re: Regarding typedef


Angrez Singh wrote:[color=blue]
> Hi,
>
> It means that you have given a new name to old unsigned data type.
> So you can use it instead of unsigned.
>
> For e.g.:
> typedef unsigned my_unsigned;
>
> my_unsigned x = 0;
>
> now x will be of type unsigned.
>
> Regards,
> Angrez[/color]

Yes.

typedef is an useful construct that the language provides. For
example,
just to explain the typedef, Symbian OS C++ provides generic data
types:

"TInt32, TInt16 and TInt8 map onto C++ built-in types in most
implementations .
These types should only be used where the size of the integer is of
first
importance."


Here, the type definition could take the following form:

typedef int TInt32;
typedef short TInt16;
typedef char TInt8;

Using typedef's in such manner provides an easy inference, ease of
portability,
etc.


Kind regards,

--
Vijay Kumar R. Zanvar
C FAQs - http://geocities.com/vijoeyz/faq/