From: Simon Wright <simon@pushface.org>
Subject: Re: Constructors with multiple inheritance
Date: Thu, 10 Nov 2011 08:33:51 +0000
Date: 2011-11-10T08:33:51+00:00 [thread overview]
Message-ID: <m2d3d0bcls.fsf@pushface.org> (raw)
In-Reply-To: 6366850.176.1320896821400.JavaMail.geo-discussion-forums@yqcm23
"Rego, P." <pvrego@gmail.com> writes:
> Maybe I can explain this easier trying to use C++. Let's suppose I
> have a class Par_Class with an integer and a pointer to a string. I
> could code, for example, (please correct me if I'm doing wrong)
>
> class Par_Class {
> public:
> Par_Class (int aValue, const char *aName);
>
> private:
> int theValue;
> char *theName;
> };
>
> the constructor could be implemented as
>
> Par_Class::Par_Class (int aValue, const char *aName){
> theValue = aValue;
> strcpy (theName, aName);
> };
>
> and finally we could instantiate this class with
>
> Par_Class Par_Obj (23, "My object is this");
>
> and sure this constructor method belongs to the class Par_Class and
> not to any other class.
Par_Class (int aValue, const char *aName) is the very special C++
constructor syntax; when used the compiler generates a new blank area of
memory and the constructor gets to fill it in.
This is *not* the same as
function Construct
(P : access Par_Class; aValue : Integer; aName : Integer_Ptr)
return Par_Class_Ptr;
which requires there to be a previous Par_Class instance; the nearest
(Ada 2012) equivalent is I think
function Construct
(aValue : Integer; aName : Integer_Ptr)
return Par_Class is
begin
return Result : Par_Class do
Result.theValue := aValue;
Result.theName := aName;
end return;
end Construct;
or, OK for Ada 95 and nearest to your present scheme:
function Construct
(aValue : Integer; aName : Integer_Ptr)
return Par_Class_Ptr is
P_Ptr : constant Par_Class_Ptr := new Par_Class;
begin
P_Ptr.theValue := aValue;
P_Ptr.theName := aName;
return P_Ptr;
end Construct;
next prev parent reply other threads:[~2011-11-10 8:33 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-29 19:40 Constructors with multiple inheritance Rego, P.
2011-09-29 20:20 ` Dmitry A. Kazakov
2011-09-30 3:11 ` Rego, P.
2011-09-30 7:36 ` Dmitry A. Kazakov
2011-09-30 14:04 ` Rego, P.
2011-09-30 16:29 ` Robert A Duff
2011-09-30 19:14 ` Rego, P.
2011-09-30 16:42 ` Dmitry A. Kazakov
2011-09-30 19:42 ` Rego, P.
2011-10-06 12:46 ` Julian Leyh
2011-11-09 2:24 ` Rego, P.
2011-11-09 8:39 ` Dmitry A. Kazakov
2011-11-10 3:47 ` Rego, P.
2011-11-10 7:09 ` AdaMagica
2011-11-10 7:20 ` AdaMagica
2011-11-10 8:35 ` Dmitry A. Kazakov
2011-11-12 15:16 ` Rego, P.
2011-11-12 15:30 ` Rego, P.
2011-11-12 16:28 ` Dmitry A. Kazakov
2011-11-12 17:41 ` Rego, P.
2011-11-10 8:33 ` Simon Wright [this message]
2011-11-10 9:01 ` Georg Bauhaus
2011-11-10 9:09 ` Georg Bauhaus
2011-11-10 18:16 ` Jeffrey Carter
2011-11-10 19:39 ` Dmitry A. Kazakov
2011-11-09 9:00 ` Simon Wright
2011-11-10 3:54 ` Rego, P.
2011-10-07 0:08 ` Shark8
replies disabled
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox