Chapter 25 - Exception Handling in C++: Here be Dragons

Abstract

This chapter focuses on exception handling in C++ environment. An exception is a situation that would be unusual for the program that is being processed. Exception handling in C++ propagates the exceptions up the stack. When errors occur, the function generating the error can throw an exception. The simple way to support the strong exception safety guarantee is to ensure that nothing is updated until programmers have executed all the steps that might throw an exception. This means taking copies of sub-objects and making the changes on the copies, prior to swapping the state between the copies and the original sub-objects. There are three rules to exception handling: destructors may not propagate exceptions; the states of two instances of a class may be swapped without an exception being thrown; and an object may own at the most one resource.