tricky_questions.cpp

#include <iostream>
#include <string>
#include <vector>

void comparisonOfIntegerWithDifferentSignedness() {
  int a = -1;

  // if we define b unsigned we will get b<a
  // unsigned int b=10;
  std::size_t b = 10;

  // change b to the signed one and the problem is gone
  // int b=10;

  std::cout << "a=" << a << " ,b=" << b << std::endl;

  // in the comparision between singed and unsigned, the signed one will turn
  // into unsigned!
  if (a < b)
    std::cout << "a<b" << std::endl;
  else
    std::cout << "b<a" << std::endl;
}

void roundingProblem() {
  float a = 1.99999999999999999;
  float b = 2;
  // you expect that result is none zero so the if true while the if is false!
  if (b - a)
    std::cout << "**" << std::endl;
  // std::cout<< b-a<<std::endl;
}

// TrackMemoryAllocations

void *operator new(size_t size) {
  std::cout << "Allocating " << size << " bytes" << std::endl;
  return malloc(size);
}

void operator delete(void *memory, size_t size) {
  std::cout << "Freeing " << size << " bytes" << std::endl;
  free(memory);
}

void operator delete(void *memory) {
  std::cout << "Freeing " << std::endl;
  free(memory);
}

void stlOnStack() {
  std::string str;
  std::cout << "allocating and freeing memory for strings" << std::endl;
  for (std::size_t i = 0; i < 25; i++) {
    str = str + std::to_string(i);
    std::cout << "size of string is: " << str.size()
              << " bytes and string is: " << str << std::endl;
  }
}

int main(int argc, char **argv) {

  // comparisonOfIntegerWithDifferentSignedness();
  // roundingProblem();
  // stlOnStack();

  return 0;
}