Question

This is a snippet of C code from a library:

typedef enum
{
/** 
  * @brief  SDIO specific error defines  
  */   
  SD_CMD_CRC_FAIL                    = (1), /*!< Command response received (but CRC check failed) */
  SD_DATA_CRC_FAIL                   = (2), /*!< Data bock sent/received (CRC check Failed) */
  SD_CMD_RSP_TIMEOUT                 = (3), /*!< Command response timeout */
  SD_DATA_TIMEOUT                    = (4), /*!< Data time out */

I do not understand the meaning of the parens around 1, 2, 3, and 4. Are SD_CMD_CRC_FAIL = 1 and SD_CMD_CRC_FAIL = (1) equivalent?

Answer 1

Yes, they are equivalent.

I don’t know why the author chose to write it like that (although see the comments to this answer for some theories).