class exit_code
{
public:
    explicit exit_code(int native_value);

    bool operator==(const exit_code &rhs) const;
    bool operator!=(const exit_code &rhs) const;

    /*
     * WIFEXITED on unix
     * true on windows
     */
    bool exited() const;

    /*
     * undefined if !exited()
     */
    int return_code() const;

    /*
     * exited() && return_code() == 0
     * is it 0 on all platforms?
     */
    bool success() const;

    int native_value() const;
};