unsigned int vs. size_t

Question

I notice that modern C and C++ code seems to use size_t instead of int/unsigned int pretty much everywhere - from parameters for C str

Answer 1

size_t is the size of a pointer.

So in 32 bits or the common ILP32 (integer, long, pointer) model size_t is 32 bits. and in 64 bits or the common LP64 (long, pointer) model size_t is 64 bits (integers are still 32 bits).

There are other models but these are the ones that g++ use (at least by default)