Not sure what subject line to use to summarize what I'm trying to do
here, but that is kind of related :)
So I would like to use an interface that inherits from another
interface, and ... well rather than describe what I'm trying to do, I
think code speaks best.
type
// here is the first interface
i_adder = interface
['{01234567-2222-407C-8133-987654FEDCBA}']
function add (a, b : longint) : longint;
end;
// this next interface inherits from i_adder, and thus does two things
i_multiplier_and_adder = interface (i_adder)
['{A1234567-2222-407C-8133-987654FEDCBA}']
function multiply (a, b : longint) : longint;
end;
t_base = TInterfacedObject;
// now an implementing class for i_adder
t_adder = class (t_base, i_adder)
function add (a, b : longint) : longint;
end;
// and finally the implementing class for i_multiplier_and_adder
t_multiplier_and_adder = class (tbase, i_multiplier_and_adder)
f_adder : i_adder;
function multiply (a, b : longint) : longint;
// THIS PROPERTY DOES NOT WORK:
property adder : i_adder read f_adder implements i_adder;
end;
The structure I have is like... I have one instance of t_adder, and I
want to have several instances of t_multiplier_and_adder that all use
the one instance of t_adder as their hook.
And in my real code, t_adder has 6 methods or so, thus it becomes
cumbersome to implement all those in t_multiplier_and_adder, each just
calling the function on the t_adder that I'd like to use as a hook.
Do I have to implement all of the individual i_adder methods for
t_multiplier_and_adder? Is there no shortcut?
Thanks!
~David.
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