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From: "Jeffrey R. Carter" <spam.jrcarter.not@spam.not.acm.org>
Newsgroups: comp.lang.ada
Subject: Re: Recommendation of safe subset of Ada to use?
Date: Sun, 6 May 2018 09:43:09 +0200
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Xref: reader02.eternal-september.org comp.lang.ada:52028
Date: 2018-05-06T09:43:09+02:00
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On 05/05/2018 11:32 PM, gorgelo@hotmail.com wrote:
>> with Ada.Text_IO; use Ada.Text_IO;
>>
>> procedure jdoodle is
>>       type Integer_Access is access all Integer;
>>        
>>       function Inner(Value : aliased in out Integer) return Integer_Access is
>>       begin
>>           return Value'Access;
>>       end Inner;
>>        
>>       function Outer return Integer_Access is
>>           Value : aliased Integer := 0;
>>       begin
>>           return Inner(Value);
>>       end Outer;
>>        
>>       Ptr : Integer_Access := Outer;  -- !!! Dangling reference
>> begin
>>       Put_Line("Hello World");
>> end jdoodle;

This seems to violate ARM 3.10.2(29): the accessibility level of Value (the 
object passed by reference to Inner) is deeper than that of the access type 
Integer_Access. I cannot find an exception to this for aliased parameters.

-- 
Jeff Carter
"It is the German who is so uncourteous to his verbs."
A Scandal in Bohemia
122