fe_cneg example

$negf = self::fe_neg($f);
        return self::fe_cmov($f, $negf, $b);
    }

    /** * @param ParagonIE_Sodium_Core_Curve25519_Fe $f * @return ParagonIE_Sodium_Core_Curve25519_Fe * @throws SodiumException */
    public static function fe_abs(ParagonIE_Sodium_Core_Curve25519_Fe $f)
    {
        return self::fe_cneg($f, self::fe_isnegative($f));
    }

    /** * Returns 0 if this field element results in all NUL bytes. * * @internal You should not use this directly from another application * * @param ParagonIE_Sodium_Core_Curve25519_Fe $f * @return int * @throws SodiumException */