Enumeration in C language

[vinothmct]

I working on low level C functions so i find a lot of code complex . Can someone explain me this piece of code?

if (req.pib_attr == ZB_PHY_PIB_CURRENT_CHANNEL)
 

  zb_mlme_get_request_t req;
 

typedef struct zb_mlme_get_request_s
{
  zb_mac_pib_attr_t  pib_attr;
  zb_uint8_t          pib_index;
} ZB_PACKED_STRUCT
zb_mlme_get_request_t;
 


typedef enum
{
  /* PHY PIB */
  ZB_PHY_PIB_CURRENT_CHANNEL                    = 0x00,
  ZB_PHY_PIB_CURRENT_PAGE                       = 0x04,
  /* MAC PIB */
  ZB_PIB_ATTRIBUTE_ACK_WAIT_DURATION            = 0x40,
  ZB_PIB_ATTRIBUTE_ASSOCIATION_PERMIT           = 0x41,
  ZB_PIB_ATTRIBUTE_AUTO_REQUEST                 = 0x42,
  ZB_PIB_ATTRIBUTE_BATT_LIFE_EXT                = 0x43,
  ZB_PIB_ATTRIBUTE_BATT_LIFE_EXT_PERIODS        = 0x44,
  ZB_PIB_ATTRIBUTE_BEACON_PAYLOAD               = 0x45,
  ZB_PIB_ATTRIBUTE_BEACON_PAYLOAD_LENGTH        = 0x46,
  ZB_PIB_ATTRIBUTE_BEACON_ORDER                 = 0x47,
  ZB_PIB_ATTRIBUTE_BEACON_TX_TIME               = 0x48,
  ZB_PIB_ATTRIBUTE_BSN                          = 0x49,
  ZB_PIB_ATTRIBUTE_COORD_EXTEND_ADDRESS         = 0x4a,
  ZB_PIB_ATTRIBUTE_COORD_SHORT_ADDRESS          = 0x4b,
  ZB_PIB_ATTRIBUTE_DSN                          = 0x4c,
  ZB_PIB_ATTRIBUTE_TIMESTAMP_SUPPORTED          = 0x5c,
  ZB_PIB_ATTRIBUTE_SECURITY_ENABLED             = 0x5d
} zb_mac_pib_attr_t;

Here enum is nested inside a structure .

If condition is checked here total enum variable req.pibattr is checked against a member of enum. I have checked values are not assigned to
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req.pib_attr
..

How the condition will be executed .

 

[dean_winchester]

hi,
the enum can not be used as a type.. here in struct, you are using enum wrongly.
just declare a variable (integer).
then check that against the enum value.