Re: Question on CRTP static member initialization with GCC

From:

Victor Bazarov <v.bazarov@comcast.invalid>

Newsgroups:

comp.lang.c++

Date:

Mon, 21 Jul 2014 23:34:53 -0400

Message-ID:

<lqkm4v$1c4$1@dont-email.me>

On 7/21/2014 9:32 PM, arkadiy@cardspring.com wrote:

I'm trying to use CRTP for static inheritance, like so:

parent.h:
template<typename Derived>
class Parent {
static int s_number;
};

child.h:
class Child : Parent<Child> {

Try to bring 's_number' to this scope with the 'using' declaration.

BTW, 's_number' is (as you have posted) private, and shouldn't be
visible in any derived classes. Perhaps you meant to declare it protected?

};

When I try to use Child::s_number I get a "Symbol not found" runtime

Runtime??

error. It seems that since template instantiation is lazy I need to
force it to initialize with:

(solution 1)

child.cpp:
template<>
int Child::Parent<Child>::s_number = 0;

[..]

I am not sure how this is going to play with your version of GCC,
however. And I didn't try it with any other compilers either. Just a
thought that occurred to me (the 'using' declaration).

V
--
I do not respond to top-posted replies, please don't ask