Re: unresolved external symbol with static variable?

From:

cbarron3@ix.netcom.com (Carl Barron)

Newsgroups:

comp.lang.c++.moderated

Date:

Sat, 31 Mar 2007 09:30:51 CST

Message-ID:

<1hvto3c.7qlxcdprl7i8N%cbarron3@ix.netcom.com>

JSprenkle@gmail.com <JSprenkle@gmail.com> wrote:

  In the faq the authors says:
  "The map is typically populated during static initialization. For
  example, if file Ellipse.cpp contains the code for derived class
  Ellipse, it would also contain a static object whose ctor adds that
  class to the map: theMap["Ellipse"] = new Ellipse()."

  What is he trying to say here?

  Any help would be appreciated.

   I think he is saying create:
    // Ellipsis.cp
    #include "Ellispsis.hpp"
    #include "Serialize.hpp" // for extern std::map<...> theMap;

    namespace
    {
        struct add_to_map
        {
              add_to_map()
              {
                  theMap["Ellipsis"] = new Ellipsis();
              }
        };
        add_to_map foo;
   }
   // impliment ellipsis don't use foo anyplace in this file
   // end of file

At least that is a literal translation.

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