sizeof in preprocessor

How can I write this correctly?

#if sizeof(int) < sizeof(my_int)
.............
#endif

I want compile different pieces of code for different platforms

"<- Chameleon ->" <cham_gss@hotmail.NOSPAM.com> wrote in message
news:c4lv0p$bbl$1@nic.grnet.gr...
> How can I write this correctly?
>
> #if sizeof(int) < sizeof(my_int)
> .............
> #endif
>
> I want compile different pieces of code for different platforms
>
>

You can't in the preprocessor but you could use
specialization of templates based on sizeof

- Chameleon - wrote:

> How can I write this correctly?
>
> #if sizeof(int) < sizeof(my_int)
> .............
> #endif

You can't. the value of sizeof() is not evaluated by the preprocessor.
Therefore, you can't use it in preprocessor conditionals. You could do:

#include <climits>
#define MY_INT_MAX some_value
#if INT_MAX < MY_INT_MAX
//something
#else
//something else
#endif

or you use templates: (untested)

template <bool b>
void my_function_internal()
{
//something
}

template <>
void my_function_internal<false>()
{
//something else
}

void my_function()
{
my_function_internal<(sizeof(int) < sizeof(my_int))>();
}