Boost Exception

throw_exception

namespace
boost
    {
#ifdef BOOST_NO_EXCEPTIONS
    void throw_exception( std::exception const & e ); // user defined
#else
    template <class E>
    void throw_exception( E const & e );
#endif
    }

Effects:

If BOOST_NO_EXCEPTIONS is not defined, boost::throw_exception(e) throws an exception of unspecified type that derives publicly from E and from boost::exception.
If BOOST_NO_EXCEPTIONS is defined, the function is left undefined, and the user is expected to supply an appropriate definition. Callers of throw_exception are allowed to assume that the function never returns; therefore, if the user-defined throw_exception returns, the behavior is undefined.

Requirements:

E must derive publicly from std::exception. E may or may not derive from boost::exception.

Notes:

The emitted exception can be intercepted as E &, std::exception &, or boost::exception &.
The emitted exception supports boost::exception_ptr.
If BOOST_EXCEPTION_DISABLE is defined and BOOST_NO_EXCEPTIONS is not defined, boost::throw_exception(e) equivalent to throw e.