[C++Quiz]#4、#116、#174

Question #174

#include<iostream>

void f(int& a, const int& b) {
  std::cout << b;
  a = 1;
  std::cout << b;
}

int main(){
  int x = 0;
  f(x,x);
}

Question #4

#include <iostream>

void f(float) { std::cout << 1; }
void f(double) { std::cout << 2; }

int main() {
  f(2.5);
  f(2.5f);
}

Question #116

#include <iostream>
#include <utility>

int y(int &) { return 1; }
int y(int &&) { return 2; }

template <class T> int f(T &&x) { return y(x); }
template <class T> int g(T &&x) { return y(std::move(x)); }
template <class T> int h(T &&x) { return y(std::forward<T>(x)); }

int main() {
  int i = 10;
  std::cout << f(i) << f(20);
  std::cout << g(i) << g(20);
  std::cout << h(i) << h(20);
  return 0;
}