namespace std::decimal {

    int fe_dec_getround();
    int fe_dec_setround(int round);  

}

namespace std::decimal {

    constexpr fexcept_t FE_DEC_DIVBYZERO;
    constexpr fexcept_t FE_DEC_INEXACT;
    constexpr fexcept_t FE_DEC_INVALID;
    constexpr fexcept_t FE_DEC_OVERFLOW;
    constexpr fexcept_t FE_DEC_UNDERFLOW;
    constexpr fexcept_t FE_DEC_ALL_EXCEPT;

    struct fenv_t;

    int fe_dec_clearexcept(int except);
    int fe_dec_raiseexcept(int except);
    int fe_dec_setexceptflag(const fexcept_t *pflag, int except);
    int fe_dec_getexceptflag(fexcept_t *pflag, int except);
    int fe_dec_testexcept(int except);
    int fe_dec_getenv(fenv_t *penv);
    int fe_dec_setenv(const fenv_t *penv);
    int fe_dec_holdexcept(fenv_t *penv);
    int fe_dec_updateenv(const fenv_t *penv);

}

// Throw std::decimal::exception if any of the exceptions in the except mask are raised.
// NB: Some operations will result in multiple floating point exceptions being raised and
// this will result in a single std::decimal::exception being thrown. The flags property of
/// this exception will include all raised exceptions.
void set_exceptions(int except) noexcept;
// Remove an exceptions in the except mask from the throw list.
void clear_exceptions(int except) noexcept;
// What exceptions have been configured to throw with set_exceptions?
int get_exceptions() noexcept;
// Check the decimal floating point environment exception flags and throw a std:decimal::exception if
// any exceptions have been raised.
// This function is called internally if any exceptions have been enabled with set_exceptions but it
// can also be called manually by the user.
void check_exceptions();

namespace std::decimal {

class exception : public std::exception
{
public:

    exception(fexcept_t flags);
    constexpr fexcept_t flags() const { return m_flags; }
    const char* what() const noexcept override { return m_what.c_str(); }

private:

    fexcept_t m_flags;
    std::string m_what;

};

}