Rule of three (C++ programming)
A RULE OF THUMB IN C++ (PRIOR TO C++11) STATING THAT IF A CLASS DEFINES ONE (OR MORE) OF DESTRUCTOR, COPY CONSTRUCTOR, OR COPY ASSIGNMENT OPERATOR, THEN IT SHOULD PROBABLY EXPLICITLY DEFINE ALL THREE
Law of the Big Three; Rule of five (C++ programming)
The rule of three and rule of five are rules of thumb in C++ for the building of exception-safe code and for formalizing rules on resource management. The rules prescribe how the default members of a class should be used to achieve these goals systematically.