- Solution

struct OnlyInt{
  OnlyInt(int){}
  template<typename T>
  OnlyInt(T) = delete;
};
int main(){
  OnlyInt(5);
  OnlyInt(5L);
  OnlyInt(5LL);
  OnlyInt(5UL);
  OnlyInt(5.5);
  OnlyInt('5');
  OnlyInt(true);
}