Can you use a.b notation in a #define macro name?

问题

I want to declare a define, using Visual Studio 2008 or 2010, like that:

#define a.b c.d

and I get following error:

error C2008: '.' : unexpected in macro definition

I see that I am allowed to create a define like this:

#define a c.d

Is the a.b notation supposed to be allowed in the macro name?

回答1:

Macros has same set of rules for naming, as do identifiers. In fact, macro-names are identifiers.

So,

• They cannot contain dot.
• They can consist of only alphabet, digits, and underscore. Nothing else. They cannot start with a digit, however.

回答2:

How about doing the follwing instead?

#define a c
#define b d

来源：https://stackoverflow.com/questions/8040391/can-you-use-a-b-notation-in-a-define-macro-name