C/C++ enums: Detect when multiple items map to same value
- by Dan
Is there a compile-time way to detect / prevent duplicate values within a C/C++ enumeration?
The catch is that there are multiple items which are initialized to explicit values.
Background:
I've inherited some C code such as the following:
#define BASE1_VAL (5)
#define BASE2_VAL (7)
typedef enum
{
MsgFoo1A = BASE1_VAL, // 5
MsgFoo1B, // 6
MsgFoo1C, // 7
MsgFoo1D, // 8
MsgFoo1E, // 9
MsgFoo2A = BASE2_VAL, // Uh oh! 7 again...
MsgFoo2B // Uh oh! 8 again...
} FOO;
The problem is that as the code grows & as developers add more messages to the MsgFoo1x group, eventually it overruns BASE2_VAL.
This code will eventually be migrated to C++, so if there is a C++-only solution (template magic?), that's OK -- but a solution that works with C and C++ is better.
