The or operator and the preprocessor?

[glen herrmannsfeldt]

error: "or" cannot be used as a macro name as it is an operator in C++

In C, the preprocessor does what its name says, and occurs before
the compiler sees tokens and reserved words.

Is that not true in C++?

extern "C" {
#include <stdio.h>
#define or "hi there!\n"
int main() {
printf( or );
}
}

 

[Ian Collins]

error: "or" cannot be used as a macro name as it is an operator in C++

In C, the preprocessor does what its name says, and occurs before
the compiler sees tokens and reserved words.

Is that not true in C++?

extern "C" {
#include<stdio.h>
#define or "hi there!\n"
int main() {
printf( or );
}
}

The error is valid, "or" is the alternative token for "||" in C++.
Redefining it is a bad idea.

 

[glen herrmannsfeldt]

(snip, I wrote)

(snip)

The error is valid, "or" is the alternative token for "||" in C++.

Oh, so also valid in preprocessor statements?

So might cause problems similar to:

#define x define

#x y 1

Redefining it is a bad idea.

Well, that is probably true of all the language keywords.
In most cases, though, it should't cause problems if you don't
use the keyword.

-- glen

 

[Ian Collins]

(snip, I wrote)


Oh, so also valid in preprocessor statements?

So might cause problems similar to:

#define x define

#x y 1


Well, that is probably true of all the language keywords.

"or" is an operator, not a keyword.