C++ Trickery : output actual enum, not its value

Question

Possible Duplicate:
C++: Print out enum value as text

Say I have an enumeration:

typedef enum MyEnum_
{
  MY_ENUM_BLUE,
  MY_ENUM_RED,
  MY_ENUM_GREEN
} MyEnum;

And that I have a method that gets an "MyEnum" as parameter. I'd like write to log file the value of that MyEnum, but I don't want 0, 1 or 2 to appear there--- I'd like to output the actual enumeration string "MY_ENUM_xxxx", of course without a switch/case block..... and dealing with each value individually.

Is there some trickery or pattern, in c++ or using macros that would help me achieve that?

I believe these are compiler constants and not compiled into the code, unlike Java and C# which have metadata for types. — Mike Christensen, Dec 12 '11 at 21:08
I know, that's why I also asked if there's a trick macro approach around this, that would alleviate the need for a lengthy switch/case block for each case... — JasonGenX, Dec 12 '11 at 21:11

score 1 · Accepted Answer · answered Dec 12 '11 at 21:10

1

No need to typedef in c++

enum MyEnum_
{
  MY_ENUM_BLUE,
  MY_ENUM_RED,
  MY_ENUM_GREEN
} MyEnum;

#define TOSTR(x) #x

const char *names[]={TOSTR(MY_ENUM_BLUE),
               TOSTR(MY_ENUM_RED),
               TOSTR(MY_ENUM_GREEN)};

int main(int argc, char *argv[])
{
   MyEnum_ e=MY_ENUM_RED;

   std::cout << names[e] << std::endl;

   return 0;
}

answered Dec 12 '11 at 21:10

Adrian Cornish

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Doesn't `enum ... {} MyEnum;` declare a global object named `MyEnum`? Isn't it simpler to write `enum MyEnum {};`? – André Caron Dec 12 '11 at 21:19
2

Note that this situation is delicate if values are assigned manually and not sequentially generated by the compiler. – André Caron Dec 12 '11 at 21:20
@AndréCaron - very true - I just c&p the OP's code – Adrian Cornish Dec 12 '11 at 21:22

C++ Trickery : output actual enum, not its value

1 Answers1