Why Can\'t I Access Protected Members in My Inherited Class When Using Template Inheritance?

Missing Parent Class Member Visibility in Inherited Class

When inheriting from a template class, such as in the case of unorderedArrayListType inheriting from arrayListType, member variables declared as protected in the parent class may not be accessible in the inherited class. This can lead to compilation errors when attempting to access these variables.

In the provided code, the error message indicates that the protected variables length and list in arrayListType are not recognized within unorderedArrayListType. To resolve this, the compiler needs to be explicitly informed that these members are inherited from the parent class.

There are two common ways to achieve this:

1. Prefacing with this->: Use this-> before each member variable reference in unorderedArrayListType, e.g., this->list, this->length.
2. Using Declarations: Include declarations in the private section of the inherited class, using the following format: using arrayListType::length;.

By declaring or prefacing member references with this->, the compiler can establish the dependency between the inherited class and the parent class template, allowing access to the protected members in the parent class.

It's important to note that failing to properly address this issue during the compilation pass can result in undefined symbol errors during the linking stage of program execution.

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