Sometimes, our code will throw an exception or error at runtime. As you may remember in our discussion of the
lexical.cpp in Chapter 3, Introducing the Boost C++ Libraries, we must sometimes use exception handling in our code, and we will now dig it up to delve into exception and error handling.
An exception is a way of reacting to a situation in which the code has exceptional circumstances by transferring control to the handler. To handle the exception, we need to use the
try-catch block in our code; then, if an exceptional circumstance arises, an exception will be thrown to the exception handler.
Now, take a look at the following code to see how exception handling is used:
/* exception.cpp */ ...