What is the primary risk of downcasting a reference without performing an explicit type check?

What defines a class as ‘abstract’ in C++?

In modern C++, what is the purpose of using ‘Concepts’ in conjunction with templates?

What happens if an abstract method is not implemented by a concrete subclass?

To use the std::sort algorithm on a collection of custom objects, what must the developer typically provide?

Why is it necessary to ‘lock’ a std::weak_ptr before accessing the data it references?

Which programming principle ensures that a container’s resources are automatically released when the object goes out of scope?

Which smart pointer should be used when a resource must have exactly one owner at any given time?

In polymorphic code, what primarily determines which fields (variables) are accessible?

Why must the stream insertion operator (