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csize-t

What is a portable method to find the maximum value of size_t?

I'd like to know the maximum value of size_t on the system my program is running. My first instinct was to use negative 1, like so:

size_t max_size = (size_t)-1;

But I'm guessing there's a better way, or a constant defined somewhere.

Solution

  • A manifest constant (a macro) exists in C99 and it is called SIZE_MAX. There's no such constant in C89/90 though.

    However, what you have in your original post is a perfectly portable method of finding the maximum value of size_t. It is guaranteed to work with any unsigned type.