Partial implementation in derived classes

From:
"Alex Vinokur" <alexvn@users.sourceforge.net>
Newsgroups:
comp.lang.c++
Date:
Fri, 5 May 2006 17:26:37 +0300
Message-ID:
<445b61f5$0$24998$834e42db@reader.greatnowhere.com>
I tried to build program with partial implementation.
However a linker generates errors.

Is there any approach that enables to use partial implementation for similar purposes?

------ foo.cpp ---
struct Base
{
  virtual void foo1() = 0;
  virtual void foo2() = 0;
};

struct Derived1 : public Base
{
  void foo1() {}
  void foo2(); // Not for use
};

struct Derived2 : public Base
{
  void foo1(); // Not for use
  void foo2() {}
};

int main ()
{
  Base* p1 = new Derived1();
  Base* p2 = new Derived2();
  // -----------------------
  // I would like to get linkage error in the following cases:
  // p1->foo2();
  // p2->foo1();
  // -----------------------
  return 0;
}
------ foo.cpp ---

------ Compilation ------
// gpp: GNU C++ 4.0.1 (DJGPP)

$ gpp foo.cpp

c:/djgpp/tmp/cccl1W22.o:foo.cpp:(.gnu.linkonce.t._ZN8Derived1C1Ev+0x16): undefined reference to `vtable for Derived1'
c:/djgpp/tmp/cccl1W22.o:foo.cpp:(.gnu.linkonce.t._ZN8Derived2C1Ev+0x16): undefined reference to `vtable for Derived2'
collect2: ld returned 1 exit status

-------------------------

 Alex Vinokur
     email: alex DOT vinokur AT gmail DOT com
     http://mathforum.org/library/view/10978.html
     http://sourceforge.net/users/alexvn

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