From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on ip-172-31-65-14.ec2.internal X-Spam-Level: X-Spam-Status: No, score=-2.9 required=3.0 tests=BAYES_00,NICE_REPLY_A autolearn=ham autolearn_force=no version=3.4.6 Path: eternal-september.org!reader02.eternal-september.org!.POSTED!not-for-mail From: "J-P. Rosen" Newsgroups: comp.lang.ada Subject: Re: Question on in/out parameters Date: Sun, 1 May 2022 09:50:03 +0200 Organization: Adalog Message-ID: References: <85d12db3-e308-46bc-9be6-20b48ebe4fd2n@googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sun, 1 May 2022 07:50:00 -0000 (UTC) Injection-Info: reader02.eternal-september.org; posting-host="a28b021dfb314ca4d6d6594a5c468529"; logging-data="29971"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19Niyg7ggV067ML0wvDzTr1" User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Cancel-Lock: sha1:N3RkwHmwfSFN6ECxM5ZB9peJg0g= In-Reply-To: Content-Language: fr Xref: reader02.eternal-september.org comp.lang.ada:63794 List-Id: Le 30/04/2022 à 13:30, reinert a écrit : > So there is no difference between "in", "in out" and "out" for > Vectors except that the compiler protests if I try to change an "in > parameter" in the actual subroutine/function? > "in" is read only, so there is a difference. The difference between "in out" and "out" is not for the compiler (in this case), but for the reader: if you declare a parameter as "out", you promise that you won't use the previous value of the parameter, and therefore that the procedure is OK if you call it with an uninitialized variable (i.e. that the procedure is appropriate to initialize an otherwise uninitialized variable). -- J-P. Rosen Adalog 2 rue du Docteur Lombard, 92441 Issy-les-Moulineaux CEDEX Tel: +33 1 45 29 21 52 https://www.adalog.fr