Know Your Integers

Standard Data Types: size_t (1)

Sizes are everywhere

  • Number of bytes in an allocated chunk of memory

  • Number of elements in an array

  • Number of microseconds until timer runs off

  • Result of the strlen() function

  • Result of the sizeof operator

This is what size_t is there for:

  • Nobody has to worry about signedness (sizes simply don’t become negative)

  • ⟶ adds clarity

#include <unistd.h>

Standard Data Types: size_t (2)


  • None (except for readability)

  • (GCC) -Wsign-compare, -Wtype-limits, …

    • lots of warnings when mixing

    • consider -Wextra

  • Correctness (up to a certain extent)

Find at least two Bugs!

size_t sum(int set[], size_t size)
    size_t sum = 0;
    while (size-- >= 0)
        sum += set[size];
    return sum;