Short note about exceptions in C++

exceptions.cpp

// C++ exceptions short-note
// Example
#include <exception>
class MyException: public std::exception 
{
    virtual const char * what() const throw()
    {
        return "Exception's description";
    }
};
// Throw
throw MyException();
// Catch
try 
{
    // Some code
}
catch(MyException & ex)
{
    std::cout << ex.what();
    // Pass forward
    throw;
}
// Catch any exception
catch(...)
{
    // Code
}
// What the hell is "throw()" after [function_name]()?
// We expect that foo can throw exceptions
void foo();
// We expect that foo can throw only exceptions type of int(DEPRECATED) 
void foo() throw(int);
// We expect that foo can't throw exceptions
void foo() throw();
// Q: So what does happen if two last functions will throw exceptions?
// A: Functions will call std::unexpected or std::terminate. 
// If std::unexpected didn't set(you can do it by std::set_unexpected) function calls std::terminate.

// noexcept(since c++11, recomended instead throw())
// We guarantee that foo don't throw exceptions
// if foo() throw exception - std::terminate called
void foo() noexcept;
// Q: Is noexcept useful? 
// A: https://akrzemi1.wordpress.com/2014/04/24/noexcept-what-for/
// Best way to use:
if(noexcept(ImportantFunction()))
{ // ImportantFunction guarantee exception safety(http://www.boost.org/community/exception_safety.html)
    // do some stuff
}
else
{ // doesn't
    // do other stuff
}