Calculation of sizof through macro. Possible?

Hi,

I need help on calculating sizeof through a macro. I have the folloing layout.

In file "One.h"

Code:

---

typedef uint16_t tTime;

---

And in file "Two.h" I want to calculate as follwing:

Code:

---

#include "One.h"

#define NODE_LENGTH 6
#define TOT_SIZE NODE_LENGTH + sizeof(tTime)

#if (TOT_SIZE > 100)
#error "TOT_SIZE too big."
#endif

---

I get the following compiling error:

Code:

---

missing binary operator before '('

---

How can I get pass this? I don't want to 'hard code' the TOT_SIZE.

Thanks in advance,
Indy

Just remove the brackets around tTime.

QuantumPete

#if is evaluated by the pre-processor
sizeof() is evaluated by the compiler.
Ne'er the twain shall meet.

You can do some funky things with templates in C++, but in C I think you're stuck with putting something like this in at the start of main.

assert( !(TOT_SIZE > 100) );

I guess I have to hard code it... can't use assert function... thanks though.

Indy

Rather than using #define, how about using a static const int? I've got a program somewhere that does something similar, let me have a look for it.

QuantumPete