Re: Access and alias

["NANCY HEHIR" <nanceh.ennis@tinet.ie>]

I am trying to use SetCommState to configure a Comm Port.
I have created a handle for COM1 using CreateFile.
SetCommState takes as it's parameters the handle and a type LPDCB (access to
the DCB)
The type LPDCB is defined in Win32-winbase.ads

Thanks for your help

Laurent Guerby wrote in message
<86d7o5ae23.fsf@ppp-169-201.villette.club-internet.fr>...

>
>Try:
>
> DCB_1 : aliased DCB;
>
>> .
>> .
>> DCB_Access:LPDCB := DCB'Access;
>>
>> compiler generates error 'prefix of "Access" attribute must be aliased'
>
>However, it is very "rare" in Ada to use aliased variables, if you're
>from a C background and try to write Ada like you write C I think
>adding "aliased" and "'access" everywhere is not the right thing to
>do. A possible guess is that you are emulating the use of "&" in C
>with aliased/access, and that the right way to do it in Ada is to use
>the "in out" parameter mode.
>
>May be if you tell us more about what you're trying to do, we can
>suggest appropriate Ada idioms (note that may be the use of aliased
>and access is the appropriate idiom here ;-).
>
>--LG