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From: 880716a@aucs.uucp (Dave Astels)
Newsgroups: comp.lang.c++
Subject: indirect message passing
Message-ID: <1990May31.131937.25923@aucs.uucp>
Date: 31 May 90 13:19:37 GMT
Article-I.D.: aucs.1990May31.131937.25923
Organization: Acadia University - School of Computer Science
Lines: 16

I am wondering if it is possible to pass messages in C++ indirectly.
Let me explain:  say I have a class X which has a member function foo().
Also, I have a variable y of type X.  Rather than invoking y.foo() directly
I want to store the information for later use.  ie. I want to set up a
callback (using X11 terminology).. to store the information that X::foo()
is to be called for the object y, then do the call later (in response to
some event, for example).  I have done this in a UI I developed in Turbo
Pascal 5.5.  I have since bought Zortech C++, and wish to eventually
rewrite the UI in C++.  The technique in TP was implemented using generic
pointers (to the object and the method entry point), and some assembly to
do the actual method invocation (supplying the Self/this parameter, etc).
-- 
- Dave

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