Re: "trivial" problem with template method pattern

From:

"Jim Langston" <tazmaster@rocketmail.com>

Newsgroups:

comp.lang.c++

Date:

Wed, 31 Oct 2007 09:06:22 -0700

Message-ID:

<hI1Wi.49$ah6.31@newsfe06.lga>

"rogo" <d.rogowski@velian.de> wrote in message
news:1193845033.943109.50860@o3g2000hsb.googlegroups.com...

Ok, when I began to implement it, I thought it should be
straightforward and easy. I'm not sure whats wrong with the following
code:

class A
{
  public:
       A() {}
       int get()
       {
           int a;
           get(a);
           return a;
       }
  protected:
       virtual void get(int&) = 0;
};

When the complier gets here it sees everything that A has, and there is no
::get(int) or A::get(int). In other words, there is no get(int) within
scope that get() can call.

Inherited classes can call functions from base classes, but base classes can
not normally call functions within derived classes.

class B : public A
{
   public:
       B(int a) : b(a) {}
  private:
       void get(int& a)
       {
           a = b;
       }
       int b;
};

int main() {
   B b(1);
   b.get();// thats a problem, and I dont know why
}

For some reason I dont understand yet the compiler can't "find" the
inherited methode "int get()". I use g++ version 4.1.2 20070925.