PARITY_NONE a keyword in C++ Windows?

Question

I am writing a serial library using boost and I have an enum:

enum parity_t { PARITY_NONE, PARITY_ODD, PARITY_EVEN };

I get errors like:

Error 1 error C2059: syntax error : '('

I couldn't figure out what the issue was. Then my friend and I tried:

void PARITY_NONE();

And we got these errors:

Error 1 error C2143: syntax error : missing ')' before 'constant'

Error 2 error C2143: syntax error : missing ';' before 'constant'

Error 3 error C2182: 'WORD' : illegal use of type 'void'

Error 4 error C2059: syntax error : ')'

I am including boost asio, which I figure is including the Windows serial api somewhere. This only occurs in Windows. As a work around I have changed my enumeration names. I cannot, however, find anything related to this issue on the internet. Can someone help us figure this out?

Answer 1

It's defined in winbase.h:

//
// Settable Stop and Parity bits.
//

#define STOPBITS_10       ((WORD)0x0001)
#define STOPBITS_15       ((WORD)0x0002)
#define STOPBITS_20       ((WORD)0x0004)
#define PARITY_NONE       ((WORD)0x0100)
#define PARITY_ODD        ((WORD)0x0200)
#define PARITY_EVEN       ((WORD)0x0400)
#define PARITY_MARK       ((WORD)0x0800)
#define PARITY_SPACE      ((WORD)0x1000)

#undef them before creating your enum.

Answer 2

It's defined in WinBase.h:

//
// Settable Stop and Parity bits.
//

#define STOPBITS_10       ((WORD)0x0001)
#define STOPBITS_15       ((WORD)0x0002)
#define STOPBITS_20       ((WORD)0x0004)
#define PARITY_NONE       ((WORD)0x0100)
#define PARITY_ODD        ((WORD)0x0200)
#define PARITY_EVEN       ((WORD)0x0400)
#define PARITY_MARK       ((WORD)0x0800)
#define PARITY_SPACE      ((WORD)0x1000)

Might aswell use their values, as they would work the same as your enum if you don't use that enum for indexing an array or the likes.

Answer 3

What's most likely happening here is one of the values in your enum is already #define to a different value. The expansion of that value is causing the enum to issue a compiler error. You can verify this by changing the code to the following

#ifdef PARITY_NONE
#error Duplicate definition
#endif

Repeat for every value in the enum

Discovering where the definition is coming from is a bit trickier. If you're lucky the following will work

• Comment out your enum definition
• Type PARITY_NONE in a method
• Right click and select "Go To Definition"