struct and union madness

struct gb_cpu {
    union {
        struct {
            union {
                struct {
                    uint8_t   : 4;
                    uint8_t C : 1;
                    uint8_t H : 1;
                    uint8_t N : 1;
                    uint8_t Z : 1;
                } flags;
                uint8_t F;
            };
            uint8_t A;
        };
        uint16_t AF;
    };
    union {
        struct {
            uint8_t C;
            uint8_t B;
        };
        uint16_t BC;
    };
    union {
        struct {
            uint8_t E;
            uint8_t D;
        };
        uint16_t DE;
    };
    union {
        struct {
            uint8_t L;
            uint8_t H;
        };
        uint16_t HL;
    };
    uint16_t PC;
    uint16_t SP;
};