Combining object-counting technique with the pseudo-constructors, we can limit the number of objects of a class.

Depending on the different input or dynamic types of function parameters, “virtualization” is a useful technique to construct new objects of different types accordingly, or to conceive of non-member functions whose behavior changes accordingly.

It’s important to have a basic understanding of the cost of some C++ features that can have a noticeable impact on the size of objects and the speed at which member functions execute.

Different libraries offering similar functionality often feature different performance trade-offs, so we might be able to remove bottlenecks by replacing one library with another.

Assignment versions of operators (such as operator+=) tend to be more efficient than stand-alone versions of those operators (e.g., operator+).