Hi,
I need help on calculating sizeof through a macro. I have the folloing layout.
In file "One.h"
And in file "Two.h" I want to calculate as follwing:Code:typedef uint16_t tTime;
I get the following compiling error: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
How can I get pass this? I don't want to 'hard code' the TOT_SIZE.Code:missing binary operator before '('
Thanks in advance,
Indy
Just remove the brackets around tTime.
QuantumPete
"No-one else has reported this problem, you're either crazy or a liar" - Dogbert Technical Support
"Have you tried turning it off and on again?" - The IT Crowd
#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) );
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
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
"No-one else has reported this problem, you're either crazy or a liar" - Dogbert Technical Support
"Have you tried turning it off and on again?" - The IT Crowd
