Re: How to make templated operator= more specific?

From:
Vidar Hasfjord <vattilah-groups@yahoo.co.uk>
Newsgroups:
comp.lang.c++.moderated
Date:
Tue, 17 Feb 2009 17:15:53 CST
Message-ID:
<5ed5a75c-1cd9-4b51-9d46-50dd87ea1997@j39g2000yqn.googlegroups.com>
On Feb 17, 4:07 pm, enjoy.c...@gmail.com wrote:

Thank you very much for answers.
It was tipo about Foo<int> fi;, i meant something like Foo fi(4);
The point was to develop exactly not templated class Foo.

so the question still open we have class Foo like:
class Foo {
public:
     template<typename T>
         Foo(T f) { bb = new Bar<T>(f); }

     template<typename T> operator Bar<T>() {
         return static_cast<Bar<T>&>(*bb);
     }

private:
     BarBase *bb;

};

now I can rephrase question:
When I declare Foo with some parameter, e.g.
Foo fi(42);
we instantiate templated Foo's contructor with type int.
How can I define exactly one conversion operator with type Bar<int>,
still having non-templated class Foo? Is it possible at all?


No.

More precisely i'd like to save type with which constructor was
instantiated.


Then you will have to make Foo a template.

I thought about typedef inside constructor, but
it's scope limited to constructor.

I know, the question is quite strange, but non-templated class Foo
leads me to beautifull design and it's handy using.


If Foo has to be a non-template, then the only solution is to use RTTI
(dynamic_cast) to check types at run-time.

Regards,
Vidar Hasfjord

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