[C++][NOTE] unsigned int overflow

 
#include <iostream>
#include <limits>

int main() {
  unsigned int i = std::numeric_limits<unsigned int>::max();
  std::cout << ++i;
}

Unsigned integers have well defined behaviour when they overflow.
When you go one above the largest representable unsigned int, you end up back at zero.
According to §3.9.1.4 in the C++ standard: "Unsigned integers, declared unsigned, shall obey the laws of arithmetic modulo 2^n where n is the number of bits in the value representation of that particular size of integer."