The Big Three are a C++ class’s destructor, copy constructor, and copy assignment operator. If one needs explicit implementation instead of the default, implement all three. section 6.2.2
Explicit copy operations must perform member-by-member copying or assignment. Coordinating these special members helps expose the automatic work that can otherwise create unnecessary operations. section 6.2.2
Instrumenting Date inside a vector
A Date class logs its constructors, assignment operator, and destructor while an Appointments vector appends, inserts, prints, and removes dates. The output reveals repeated copies, destructions, allocations, and deallocations, turning an apparently simple test into a performance diagnosis. section 6.2.2
