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  1. #include <iostream>
  2. #include <sstream>
  3. using namespace std;
  4.  
  5. template <int N> struct Array : Array <N - 1>
  6. {
  7.     double x;
  8.  
  9.     template<int M> double& comp() { return Array<M>::x; }
  10.     template<int M> const double& comp() const { return Array<M>::x; }
  11.  
  12.     //Prints vector
  13.     ostream& print(ostream& out) const
  14.     {
  15.         static_cast<const Array<N-1>*>(this)->print(out);
  16.         out << ", " <<x;
  17.         return out;
  18.     }
  19.  
  20.     double& operator[] (int i) {
  21.     	return reinterpret_cast<double*>(this)[i];
  22. 	}
  23.  
  24.  
  25.     //Vector in place summation, without looping
  26.     Array& operator+=(const Array& v)
  27.     {
  28.         x+=v.x;
  29.         *static_cast<Array<N-1>*>(this) += static_cast<const Array<N-1>&>(v);
  30.         return *this;
  31.     }
  32. };
  33.  
  34. template <> struct Array<1>
  35. {
  36.     double x;
  37.  
  38.     template<int M> double& comp() { return Array<M>::x; }
  39.     template<int M> const double& comp() const { return Array<M>::x; }
  40.  
  41.     //Prints vector
  42.     ostream& print(ostream& out) const
  43.     {
  44.         out << x;
  45.         return out;
  46.     }
  47.  
  48.     double& operator[](int i) {
  49.     	return *reinterpret_cast<double*>(this); 
  50. 	}
  51.  
  52.     //Vector in place summation, without looping
  53.     Array& operator+=(const Array& v)
  54.     {
  55.         x+=v.x;
  56.         return *this;
  57.     }
  58. };
  59.  
  60. template<int N>
  61. ostream& operator<<(ostream& out, const Array<N>& v)
  62. {
  63.     out << "("; v.print(out); out << ")";
  64.     return out;
  65. }
  66.  
  67. int main() {
  68. 	Array<3> vec;
  69.  
  70. 	vec[0] = 1; vec[1] = 2; vec[2] = 3;
  71.  
  72. 	cout << vec << endl;
  73.  
  74. 	cout << (vec+=vec) << endl;
  75.  
  76. 	return 0;
  77. }
Success #stdin #stdout 0s 3468KB
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https://ideone.com/bpQXDo
language:
C++ (gcc 8.3)
created:
9 years ago
visibility:
public

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