C++ Riddle - changes in the spec - Oct-02, 2022

In her great talk at recent CppCon 2022 titled “A Tour of C++ Recognised User Type Categories”, Nina Ranns mentioned a type category defined in the C++ specification which changed its requirements in any version of the C++ spec since C++11 and up to C++20.

And the question is:
What is this type category, what are the changes made in its requirements in each spec version and why?

1 Like