Re: Interfacing to C library...

["Eric G. Miller" <egm2@jps-nospam.net>]

In <wccpttm1txo.fsf@shell01.TheWorld.com>, Robert A Duff wrote:

> "Eric G. Miller" <egm2@jps-nospam.net> writes:

>> Aha! I missed that you couldn't mix "in/out" w/ "access" in a subprogram
>> parameter list declaration/definition. Okay, definitely nicer than defining
>> 40 access to record types...
> 
> You *can* mix 'in out' with 'access':
> 
>     procedure P(X: in out R; Y: access R);
> 
> is legal.  Perhaps what you're thinking of is the fact that functions do
> not allow 'in out' parameters, so sometimes people use access parameters
> instead, when they want a function to have side effects on its
> parameters.  C functions do that all the time -- e.g., you pass a
> "char *", and the function writes upon the thing pointed-to, and *also*
> returns some sort of status code.

I was thinking of 6.1.15
                                                                                                      
   parameter_specification ::=                                                                             
       defining_identifier_list : mode  subtype_mark [:= default_expression]                               
     | defining_identifier_list : access_definition [:= default_expression] 

procedure Foo (Thing : in out access Bar);

But, I suppose that doesn't make any sense...  Anyway, thanks for the
help...