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From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: Possible to recover default value of scalar type?
Date: Mon, 14 Dec 2020 19:26:10 -0600
Organization: JSA Research & Innovation
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"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message 
news:rr7bqv$19da$1@gioia.aioe.org...
> On 2020-12-14 10:01, AdaMagica wrote:
>> I do not really understand the problem. It seems you want to be able to 
>> access the default value like so:
>> N: Natural := Natural(A_Type'Default_Value);
>> This is not possible. Thre is no corresponding attribute 'Default_Value.
>> If this presents a real problem, submit it to Ada comment stating why 
>> this is important.
>
> It could in the cases like this:
>
>    procedure Library_Foo (Bar : Baz := Baz'Default_Value)

I would have suggested to write this as:
     procedure Library_Foo (Bar : Baz := <>)
since this is the syntax used in aggregates (and why should aggregates have 
all the fun??).

>    Put_Line (String (1..10)'Default_Value); -- print garbage

The above isn't a legal attribute prefix in any case (can't slice a type). 
And you don't need to because this is clearly an aggregate (which is legal 
in Ada 2012):
    Put_Line (String'(1..10 => <>)); -- print garbage

                                Randy.