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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Possible to recover default value of scalar type?
Date: Mon, 14 Dec 2020 17:31:29 +0100
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On 2020-12-14 16:56, AdaMagica wrote:
> Dmitry A. Kazakov schrieb am Montag, 14. Dezember 2020 um 10:38:42 UTC+1:
>> procedure Library_Foo (Bar : Baz := Baz'Default_Value)
> Suppose type Baz has no default value aspect. Then a call Library_Foo without parameter would use what?

The default used by the compiler in this:

    declare
       Bar : Baz;
    begin

with an appropriate warning of course.

[ It was a language design bug to allow implicitly uninitialized 
variables in the first place. Declarations like above should have been 
illegal. ]

> A solution could be that the attribute is illegal if there is no aspect. The compiler knows.

I would argue that if

    declare
       Bar : Baz;
    begin

is legal, then it must be logically equivalent to:

    declare
       Bar : Baz := Baz'Default_Value;
    begin

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de