From: "G.B." <bauhaus@notmyhomepage.invalid>
Subject: Re: A function that cannot be called?
Date: Sun, 21 Oct 2018 12:14:03 +0200
Date: 2018-10-21T12:14:03+02:00 [thread overview]
Message-ID: <pqhjhc$5vr$1@dont-email.me> (raw)
In-Reply-To: <d8e778fb-09d0-4989-b1e0-76b3148211f5@googlegroups.com>
On 20.10.18 00:06, Jere wrote:
> Are you ok with runtime checks? If so, you can create a separate package
> for the void type:
>
> package Voids is
> type Void is limited private;
> private
> type Void is new Ada.Finalization.Limited_Controlled
> with null record;
> overriding procedure Initialize(Self : in out Void);
> end Voids;
> package body Voids is
> procedure Initialize(Self : in out Void) is
> begin
> raise Program_Error;
> end Initialize;
> end Voids;
>
> Here, if try to create a variable of type Void, it will raise
> Program_Error (or you can add a custom exception. Same for if
> you call a function that tries to return a Voids.Void variable.
I like the idea because the compiler will probably not suppress
raising the exception. This is unlike relying on Constraint_Error
being raised for 1..0. The not null constraint on a component
triggers C_E not matter what, it seems. However, Initialize states
the intention directly.
next prev parent reply other threads:[~2018-10-21 10:14 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-18 12:14 A function that cannot be called? G.B.
2018-10-18 15:33 ` Stefan.Lucks
2018-10-18 20:21 ` G.B.
2018-10-18 20:57 ` Niklas Holsti
2018-10-19 7:15 ` Dmitry A. Kazakov
2018-10-19 13:55 ` G.B.
2018-10-19 15:31 ` Dmitry A. Kazakov
2018-10-18 17:03 ` AdaMagica
2018-10-18 19:36 ` G.B.
2018-10-18 21:30 ` Randy Brukardt
2018-10-19 14:00 ` G.B.
2018-10-19 15:39 ` Dmitry A. Kazakov
2018-10-20 1:34 ` Randy Brukardt
2018-10-20 9:14 ` G.B.
2018-10-20 11:13 ` Simon Wright
2018-10-20 14:11 ` Dmitry A. Kazakov
2018-10-21 9:25 ` G.B.
2018-10-21 9:07 ` G.B.
2018-10-21 9:51 ` Dmitry A. Kazakov
2018-10-21 10:57 ` Niklas Holsti
2018-10-21 18:00 ` Simon Wright
2018-10-19 8:48 ` AdaMagica
2018-10-19 11:15 ` G.B.
2018-10-19 17:06 ` AdaMagica
2018-10-19 19:57 ` G.B.
2018-10-19 22:06 ` Jere
2018-10-21 10:14 ` G.B. [this message]
2018-10-21 11:30 ` Egil H H
2018-10-23 11:45 ` G.B.
2018-10-23 14:35 ` Jere
2018-10-23 14:57 ` Dmitry A. Kazakov
2018-10-23 17:49 ` G.B.
2018-10-23 19:25 ` Dmitry A. Kazakov
2018-10-24 7:35 ` G.B.
2018-10-24 8:14 ` Dmitry A. Kazakov
2018-10-19 18:19 ` marciant
2018-10-19 18:22 ` marciant
2018-10-20 1:36 ` Randy Brukardt
2018-10-20 2:54 ` marciant
2018-10-19 20:25 ` Shark8
2018-10-19 23:28 ` marciant
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