CppCon 2023

“Regular” is not exactly a new concept. If we reflect back on STL and its design principles, as best described by Alexander Stepanov in his “Fundamentals of Generic Programming” paper, we see that regular types naturally appear as necessary foundational concepts in programming. Why do we need to bother with such taxonomies? Because STL assumes such properties about the types it deals with and imposes such conceptual requirements for its data structures and algorithms to work properly.
STL vocabulary types such as string_view, span, optional, expected etc., raise new questions regarding values types, whole-part semantics, copies, composite objects, ordering and equality.
Designing and implementing regular types is crucial in everyday programming, not just library design. Properly constraining types and function prototypes will result in intuitive usage; conversely, breaking subtle contracts for functions and algorithms will result in unexpected behavior for the caller.
This talk will explore the relation between Regular types (plus other concepts) and STL constructs, with examples, common pitfalls and guidance.