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Subject: Re: In mode parameter in an assignment statement
Newsgroups: comp.lang.ada
References: <82fdea5d-b9b6-4f1e-a45f-ee0ff9f55946@googlegroups.com>
From: Per Sandberg <per.s.sandberg@bahnhof.se>
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Date: 2018-10-13T08:03:00+02:00
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package GNATCOLL.Mmap is
....
private
    type Mapped_Region_Record;
    type Mapped_Region is access Mapped_Region_Record;
...
end GNATCOLL.Mmap;

If you look in the spec you will see that Mapped_Region is an access 
type referencing the incomplete Mapped_Region_Record that is completed 
in the body, any yes the implicit deference makes it look a bit strange.
/P


On 10/13/18 2:48 AM, Anh Vo wrote:
>     -- ...
> 
>     ------------------
>     -- Compute_Data --
>     ------------------
> 
>     procedure Compute_Data (Region : Mapped_Region) is
>        Data_Shift : constant Storage_Offset :=
>           Storage_Offset (Region.User_Offset - Region.System_Offset);
>     begin
>        if Region.User_Size = 0 then
>           Region.Data := Empty_String'Address;
>        elsif Region.Mapped then
>           Region.Data := Region.Mapping.Address + Data_Shift;
>        else
>           Region.Data := Region.Buffer.all'Address + Data_Shift;
>        end if;
>     end Compute_Data;
> 
> end GNATCOLL.Mmap;
> 
> The above code is the tail end of package gnatcoll-mmap.adb.
> 
> I thought it should be rejected during compilation because in mode parameter is not allowed in an assignment statement. But, it was compiled successfully under GNAT obviously.
> 
> What did I miss? Thanks in advance.
> 
> Anh Vo
>