Use of undeclared identifier in C++ with templates and inheritance [duplicate]

Answer 1

It's due to template inheritance. In such case you should mannualy specify using for base methods:

template 
MyDerived::doSomething() {
  using MyBase::addStuff;
  T* thingy = new T();
  addStuff(thingy); 
}

or do it by this pointer:

template 
MyDerived::doSomething() {
  T* thingy = new T();
  this->addStuff(thingy); 
}