CODEWITHSUNDEEP
c++macros
Eutherpy
Eutherpy

Reputation: 4571

"unexpected in macro definition"

I wrote 

#ifndef Header1.h
#define Header1.h

class Complex
{
   [...]
};

#endif

in my project (Visual Studio 2010) and I get an Error C2008: '.' : unexpected in macro definition. I don't understand what the problem is with "Header1.h" or how to fix it.

Upvotes: 0

Views: 5731

Answers (4)

Shafik Yaghmour
Shafik Yaghmour

Reputation: 158449

You need to use an identifier here:

#ifndef Header1.h
        ^^^^^^^^^

and they can not include . in them, we can see this from the draft C++ standard section 16 Preprocessing directives paragraph 1 which includes the following grammar:

# ifdef identifier new-line groupopt
        ^^^^^^^^^^
# ifndef identifier new-line groupopt
         ^^^^^^^^^^

typically include guards are all caps and an underscores:

 #ifndef HEADER1_H

Upvotes: 2

pvoosten
pvoosten

Reputation: 3287

A macro name should not contain a dot. You'd better use

#ifndef HEADER1_H
#define HEADER1_H

...

#endif

Upvotes: 1

Collin Dauphinee
Collin Dauphinee

Reputation: 13973

Macro names can't contain periods. Rename it to Header1 or Header1h.

As an aside, it's standard for most macros to be ALL_UPPERCASE.

Upvotes: 1

Montaldo
Montaldo

Reputation: 863

Don't use the . use an _ instead

#ifndef HEADER1_H
#define HEADER1_H

class Complex
{
   [...]
};

#endif

Upvotes: 4

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