From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-0.9 required=5.0 tests=BAYES_00,FORGED_GMAIL_RCVD, FREEMAIL_FROM autolearn=no autolearn_force=no version=3.4.4 X-Google-Thread: 103376,ffef1fd08e45df0c X-Google-Attributes: gid103376,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news2.google.com!postnews.google.com!56g2000hsm.googlegroups.com!not-for-mail From: "ophir.geffen@gmail.com" Newsgroups: comp.lang.ada Subject: Re: using put procedure with a generic package Date: Wed, 7 May 2008 21:48:47 -0700 (PDT) Organization: http://groups.google.com Message-ID: References: <151bc418-a6e4-47ef-ab7f-5b93a3cedb58@r66g2000hsg.googlegroups.com> NNTP-Posting-Host: 84.228.83.197 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Trace: posting.google.com 1210222127 5329 127.0.0.1 (8 May 2008 04:48:47 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Thu, 8 May 2008 04:48:47 +0000 (UTC) Complaints-To: groups-abuse@google.com Injection-Info: 56g2000hsm.googlegroups.com; posting-host=84.228.83.197; posting-account=lm8QOAoAAABTtES85uhrtpkmFliOTt7J User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.8.1.14) Gecko/20080410 SUSE/2.0.0.14-0.1 Firefox/2.0.0.14,gzip(gfe),gzip(gfe) Xref: g2news2.google.com comp.lang.ada:5747 Date: 2008-05-07T21:48:47-07:00 List-Id: On May 8, 7:09 am, "Jeffrey R. Carter" wrote: > ophir.gef...@gmail.com wrote: > > > * queues.ads: > > with Ada.Text_IO; > > generic > > type Item is private; > > with procedure Item_Put(The_Item : in Item); > > Item_Put has exactly one parameter. > > > package Int_IO is new Ada.Text_IO.Integer_IO(Integer); > > package Int_Queues is new Queues(Item => Integer, Item_Put => > > Int_IO.Put); --- error here > > > The package compiles on its own, but when I try to compile Test_Queues > > there is an error: > > no visible subprogram matches the specification for "Item_Put" > > Ada.Text_IO.Integer_IO has the following procedures named Put: > > procedure Put(File : in File_Type; > Item : in Num; > Width : in Field := Default_Width; > Base : in Number_Base := Default_Base); > > procedure Put(Item : in Num; > Width : in Field := Default_Width; > Base : in Number_Base := Default_Base); > > procedure Put(To : out String; > Item : in Num; > Base : in Number_Base := Default_Base); > > None of these has exactly one parameter. That's why Int_IO.Put doesn't match > Item_Put. > > You can call the 2nd of these with only one explicit parameter: > > Int_IO.Put (Item => 7); > > but it still has 3 parameters; the other 2 get the default values as the actual > parameters. > > You need to create a procedure that matches Item_Put: > > procedure Put (Item : in Integer) is > -- null; > begin -- Put > Int_IO.Put (Item => Item); > end Put; > > and use it to instantiate your generic package. > > -- > Jeff Carter > "I unclog my nose towards you." > Monty Python & the Holy Grail > 11 Hi Thanks for the quick reply The problem is that the package needs to know how to handle most non- limited types like Integer, String, Client, Plane, Book, Document, ... The Put procedure in any of those might and should be different from Put Integer. And I don't want to force the package user to declare a special Put procedure with only one var. Is there a better way to write the package and/or a more correct way to declare it when using it?