Re: nondependent base in templates

From:
=?ISO-8859-1?Q?Daniel_Kr=FCgler?= <daniel.kruegler@googlemail.com>
Newsgroups:
comp.lang.c++.moderated
Date:
Wed, 28 Oct 2009 17:14:03 CST
Message-ID:
<78bf287c-e49f-4da5-844a-565e27c53abe@u36g2000prn.googlegroups.com>
On 28 Okt., 14:03, muler <mulugeta.abe...@gmail.com> wrote:

Hi,

Consider this:

template <class X>
class Base {
public:
    typedef double T;

};

template <class T>
class Derived : Base<int> { // nondependent base
public:
    T strange_; // T is Base<int>::T (i.e, double) not template
parameter T

};

Question: how can I refer to the template parameter T in the derived
class without:
1) changing its name, and
2) changing the typedef in Base ?


3) Changing the template parameter name T in derived

No kidding, this is a nasty problem which is
intensively debated on

http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#459

My personal guess is that it won't be fixed for
C++0x. No, no-one told me that, but it's rather
probable given the history of the issue and the
time-line for C++0x.

IMO currently we can only reduce the risks by
proper naming conventions. While I consider the
problem as nasty, I never met it personally,
because I never had a naming clash of a member
typedef with a template parameter name.

HTH & Greetings from Bremen,

Daniel Kr?gler

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