How can one print a size_t variable portably using the printf family?

Question

I have a variable of type size_t, and I want to print it using printf(). What format specifier do I use to print it portably?

In 32-bit ma

Answer 1

Looks like it varies depending on what compiler you're using (blech):

• gnu says %zu (or %zx, or %zd but that displays it as though it were signed, etc.)
• Microsoft says %Iu (or %Ix, or %Id but again that's signed, etc.) — but as of cl v19 (in Visual Studio 2015), Microsoft supports %zu (see this reply to this comment)

...and of course, if you're using C++, you can use cout instead as suggested by AraK.