NOTE: If you are using C++11 or newer and Boost 1.75 or newer, you might consider using Boost LEAF instead of Boost Exception.
The purpose of Boost Exception is to ease the design of exception class hierarchies and to help write exception handling and error reporting code.
It supports transporting of arbitrary data to the catch site, which is otherwise tricky due to the no-throw requirements (15.5.1) for exception types. Data can be added to any exception object, either directly in the throw-expression (15.1), or at a later time as the exception object propagates up the call stack.