#include <exception>
#include <iostream>

class Exception : public std::exception {
    public:
	Exception() { }
	virtual ~Exception() throw() { }
	virtual const char *what() {
	    return _message.c_str();
	}

    protected:
	const std::string _message;
};

class FooException : public Exception {
    public:
	FooException() : _message("FooException") { }
	virtual ~FooException() throw() { }

    protected:
	const std::string _message;
};

void throw_foo() {
    throw FooException();
}

int main() {
    throw_foo();

    return 0;
}