From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.5-pre1 (2020-06-20) on ip-172-31-74-118.ec2.internal X-Spam-Level: X-Spam-Status: No, score=-1.9 required=3.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.5-pre1 Date: 22 Apr 92 15:38:11 GMT From: mcsun!ub4b!cfmu!news@uunet.uu.net (Stef Van Vlierberghe) Subject: Survey : use of limited private types Message-ID: <1992Apr22.153811.11769@cfmu.eurocontrol.be> List-Id: A few weeks ago on the ISO-WG9 meeting on the Ada9X project, I tried to reraise the issue of type abstraction and user-defined assignment. The "answer" seemed to be "use limited types, export procedure ASSIGN, and live with all the known limitations of limited types", since for non-published reasons "user-defined assignment was considered too complex an issue". A reference to the C++ support for the paradigm invoked only adverse response. Therefore a little survey. Everyone that replies by email will receive a report that summarizes all replies, so you can directly reply to stef@cfmu.eurocontrol.be or post of follow-up article. I have major difficulty selling the answer quoted above in our environment. Most programmers had a little experience with limited types, enough to scare them off, and are very reluctant to try once more. Has anyone experience with abstract data types that need control over equality or assignment? Were limited types used in this case (as the "answer" above suggests)? Or did you simply rely or the predefined assignment not being used? Do you use components that do not support generic formal limited types (such as most Booch components), or do you use components that do ? Were these acquired externally (reference if possible) or developed in-house (sample or spec if possible) ? Do you know of any published information about the INFEASIBILITY of user-defined assignment? -- Stef VAN VLIERBERGHE Eurocontrol - Central Flow Management Unit stef@cfmu.eurocontrol.be Avenue des Arts 19H Tel: +32 2 729 33 42 B-1040 BRUSSELS Fax: +32 2 729 32 16 Belgium