Exception handling
Programming in C++ language - Concepts

C++ has an exception handling mechanism. An exception is a sequence break (not a function call!) triggered (or "thrown") by a program using the throw instruction, in which any expression is mentioned. The program then branches to a set of instructions, known as an "exception handler", chosen according to the nature of the expression specified in the throw instruction.

For a portion of the program to intercept an exception, it must appear within a block preceded by the try keyword. The latter must be followed by one or more catch instructions representing the various corresponding handlers, as in this diagram :