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- From: James Kanze US/ESC 60/3/141 #40763 <kanze@lts.sel.alcatel.de>
- Message-ID: <9602020959.AA02291@lts.sel.alcatel.de>
- X-Original-Date: Fri, 2 Feb 96 10:59:13 +0100
- Path: in1.uu.net!bounce-back
- Date: 03 Feb 96 04:48:42 GMT
- Approved: fjh@cs.mu.oz.au
- In-Reply-To: Valentin Bonnard's message of 01 Feb 96 17:10:01 GMT
- Newsgroups: comp.std.c++
- Subject: Re: Give operator. a chance
- References: <3102AD11.1663@et.se> <4e0pj1$rq6@news.bridge.net> <9601260532.14152@mulga.cs.mu.OZ.AU> <4eqr6b$778@s3.iway.fr>
- Organization: GABI Software, Sarl.
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- In article <4eqr6b$778@s3.iway.fr> Valentin Bonnard
- <bonnardv@pratique.fr> writes:
-
- |> First of all, I suppose there is no difference bewten A + B,
- |> A.operator+ (B) and A.plus (B) when operator+ is defined as plus.
-
- |> Suppose first you overload operator+, then you overload operator. in
- |> MyClass:
-
- |> class MyClass {
- |> private:
- |> AnnotherClass* theOtherClass;
- |> public:
- |> AnnotherClass operator. ();
- |> MyClass operator+ (int);
- |> void Something_only_defined_in_MyClass ();
- |> };
-
- |> MyClass A;
-
- |> A + 2; is equivalent with A.operator (2) and (A.operator.).operator (2)
-
- No, at least not as I understand the proposal. A + 2 causes
- MyClass::operator+ to be called, with &A as this, and 2 as the
- argument. The operator.() function would only be called when a `.'
- appears in the equation.
-
- |> You can't even write (&A)->Something_only_defined_in_MyClass () in
- |> order to access Something_only_defined_in_MyClass (which is only
- |> defined for MyClass): (&A)->a_member is equivalent with
- |> ((A.operator.).operator&)->a_member.
-
- No, the type of `&A' is MyClass*. There is no operator.() defined for
- this type, nor can there ever be. There is an operator-> defined, the
- built in one.
-
- If I write (&A)->, the compiler uses (the built-in) operator&, then
- operator-> on the results. What makes you think it could do anything
- else?
-
- |> How can yu access Something_only_defined_in_MyClass ?
-
- |> If operator. return theOtherClass, why don't you just write:
- |> AnnotherClass* theOtherClass;
-
- Because typically, `AnotherClass' is a proxy class (a smart
- reference), the user doesn't even know about it, and cannot name it if
- he is (since it will be declared private in the container class).
-
- --
- James Kanze Tel.: (+33) 88 14 49 00 email: kanze@gabi-soft.fr
- GABI Software, Sarl., 8 rue des Francs-Bourgeois, F-67000 Strasbourg, France
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