Clean code to printf size_t in C++ (or: Nearest equivalent of C99's %z in C++)

Question

I have some C++ code that prints a size_t:

size_t a;
printf(\"%lu\", a);

I\'d like this to compile without warnings on both 32

Answer 1

C++11

C++11 imports C99 so std::printf should support the C99 %zu format specifier.

C++98

On most platforms, size_t and uintptr_t are equivalent, in which case you can use the PRIuPTR macro defined in :

size_t a = 42;
printf("If the answer is %" PRIuPTR " then what is the question?\n", a);

If you really want to be safe, cast to uintmax_t and use PRIuMAX:

printf("If the answer is %" PRIuMAX " then what is the question?\n", static_cast(a));