strlen in the C preprocessor?

Question

Is it possible to implement strlen() in the C preprocessor?

Given:

#define MYSTRING \"bob\"

Is there

Answer 1

It doesn't use the preprocessor, but sizeof is resolved at compile time. If your string is in an array, you can use that to determine its length at compile time:

static const char string[] = "bob";
#define STRLEN(s) (sizeof(s)/sizeof(s[0]))

Keep in mind the fact that STRLEN above will include the null terminator, unlike strlen().