Converting C++ enums to strings

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Introduction

This code is used to convert a C++ enumeration value to its equivalent string representation. It is useful, for example, to debug your code, or generate trace messages.

Using the code

Create a header file called "EnumToString.h" with the following contents:

// File name: "EnumToString.h"

#undef DECL_ENUM_ELEMENT
#undef BEGIN_ENUM
#undef END_ENUM

#ifndef GENERATE_ENUM_STRINGS
    #define DECL_ENUM_ELEMENT( element ) element
    #define BEGIN_ENUM( ENUM_NAME ) typedef enum tag##ENUM_NAME
    #define END_ENUM( ENUM_NAME ) ENUM_NAME; \
            char* GetString##ENUM_NAME(enum tag##ENUM_NAME index);
#else
    #define DECL_ENUM_ELEMENT( element ) #element
    #define BEGIN_ENUM( ENUM_NAME ) char* gs_##ENUM_NAME [] =
    #define END_ENUM( ENUM_NAME ) ; char* GetString##ENUM_NAME(enum \
            tag##ENUM_NAME index){ return gs_##ENUM_NAME [index]; }
#endif

Put your enum in a specific header file using a special syntax. For example, the enum:

enum Days
{
   sunday,
   monday,
   tuesday,
   wednesday,
   thursday,
   friday,
   saturday
};

will become a header file called "Days.h" with the following contents:

// File name: "Days.h"

#if ( !defined(DAYS_H) || defined(GENERATE_ENUM_STRINGS) )

#if (!defined(GENERATE_ENUM_STRINGS))
    #define DAYS_H
#endif

#include "EnumToString.h"


///////////////////////////////

// The enum declaration

///////////////////////////////

BEGIN_ENUM(Days)
{
    DECL_ENUM_ELEMENT(sunday),
    DECL_ENUM_ELEMENT(monday),
    DECL_ENUM_ELEMENT(tuesday),
    DECL_ENUM_ELEMENT(wednesday),
    DECL_ENUM_ELEMENT(thursday),
    DECL_ENUM_ELEMENT(friday),
    DECL_ENUM_ELEMENT(saturday)
}
END_ENUM(Days)

#endif // (!defined(DAYS_H) || defined(GENERATE_ENUM_STRINGS))

Include the file "Days.h" everywhere you need the enum Days. Use it like a normal enumeration:

#include "Days.h"


void MyFunction( Days day )
{
    CString message;
    switch( day )
    {
        case monday:
        case tuesday:
        case wednesday:
        case thursday:
        case friday:
        {
            message.Format("Today is %s, I have to work!", 
                           GetStringDays(day) );
        }
        break;

        case saturday:
        case sunday:
        {
            message.Format("Today is %s, very nice!!!", 
                           GetStringDays(day) );
        }
        break;
    }
    AfxMessageBox(message);                       
}

Create a CPP module where the strings associated to enums are actually defined:

// File name: "EnumToString.cpp"


/// The strings associated with the enums are gererated here

/////////////////////////////////////////////////////////////////////

#define GENERATE_ENUM_STRINGS  // Start string generation

#include "Days.h"             

#include "OtherEnum.h"

#include "AnotherOne.h"

#undef GENERATE_ENUM_STRINGS   // Stop string generation