Never return a pointer or reference to a local stack object, a refenrence to a heap-allocated object, or a pointer or reference to a local static object if there is a change that more than one such object will be needed (item 4 provides a “counter” example that is reasonable in single-threaded environments).

Pass by reference-to-const is typically more efficient than pass by value and avoids the slicing problem.

Before definining a new type, be sure to consider all the issues discussed in this item.

Good interfaces are easy to use correctly and hard to use incorrectly.

Failure to do this can lead to subtle resource leaks when exceptions are thrown.