directive #if and operator sizeof

[andi.martin]

Hi,

AFAIK the sizeof operator returns a constant expression (integer type).
So why
#if sizeof(char)==1
emits a compiler error..?

Regards,
Andreas Martin

[JohnF]

Hi,

AFAIK the sizeof operator returns a constant expression (integer type).
So why
#if sizeof(char)==1
emits a compiler error..?

Regards,
Andreas Martin

I would imagine that using it in a pre-processing context is disallowed.

John

[pgoh]

John is correct. sizeof is evaluated at compile time, while the preprocessor is evaluated before compilation.