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

The fmt library provides a fast portable (and safe) implementation of printf including the z modifier for size_t:

#include "fmt/printf.h"

size_t a = 42;

int main() {
  fmt::printf("%zu", a);
}

In addition to that it supports Python-like format string syntax and captures type information so that you don't have to provide it manually:

fmt::print("{}", a);

It has been tested with major compilers and provides consistent output across platforms.

Disclaimer: I'm the author of this library.