将ctype宏转换为c ++常量的方法

Question

I have a c++ library which is defined the MACROS like below,

/* this is defined is the result header file*/

#define RESULT_ENUM( prefix, name, value )  prefix ## name = (value)

#define STATE_RESULT_LIST( prefix ) \
RESULT_ENUM( prefix, SUCCESS,                        0 ), \
RESULT_ENUM( prefix, PENDING,                        1 ),

#define COMMON_RESULT_LIST( prefix ) \
RESULT_ENUM( prefix, SUCCESS,                        0 ), \
RESULT_ENUM( prefix, PENDING,                        1 ),

typedef enum
{
  STATE_RESULT_LIST     ( STATE_          ) 
  COMMON_RESULT_LIST    ( CHANNEL_        )
}domain_result;

This is how its used

int main(int argc, char** argv) {
domain_result res = CHANNEL_SUCCESS;
cout<<STATE_SUCCESS <<endl;
cout<<CHANNEL_PENDING<<endl;
return 0;
}

as everyone suggests that we should not use macros, now I dont want to change the c++ source files, need changes only headerfile.

So how to convert these in to c++ style enums and static constants.?

Answer 1

You can use g++ -E to figure out how domain_result gets defined in the end.

As it turns out, all of that can be replaced by:

enum domain_result
{
   STATE_SUCCESS = 0,
   STATE_PENDING = 1,
   CHANNEL_SUCCESS = 0,
   CHANNEL_PENDING = 1,
};

If there is a need to have all the tokens of the enum to have unique values, you can simplify that to:

enum domain_result
{
   STATE_SUCCESS, // = 0 by default.
   STATE_PENDING,
   CHANNEL_SUCCESS,
   CHANNEL_PENDING,
};

Answer 2

option 1:

enum domain_result : uint8_t
{
    STATE_SUCCESS = 0,
    STATE_PENDING = 1,
    CHANNEL_SUCCESS = 0,
    CHANNEL_PENDING = 1,
};

option 2:

const uint8_t STATE_SUCCESS = 0;
const uint8_t STATE_PENDING = 1;
const uint8_t CHANNEL_SUCCESS = 0;
const uint8_t CHANNEL_PENDING = 1;