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  1. template<typename A1>
  2. struct AbstractBinder
  3. {
  4.     virtual void call(A1 a1)=0;
  5.     virtual AbstractBinder<A1> *clone()=0;
  6.     virtual ~AbstractBinder(){}
  7. };
  8.  
  9. template<typename A1, typename I, typename M>
  10. struct Binder : AbstractBinder<A1>
  11. {
  12.     Binder(I i, M m) : i_(i), m_(m) { }
  13.     void call(A1 a1)
  14.     {
  15.         (i_->*m_)(a1);
  16.     }
  17.     virtual AbstractBinder<A1> *clone()
  18.     {
  19.         return new Binder(*this);
  20.     }
  21.     I i_;
  22.     M m_;
  23. };
  24.  
  25. template<typename A1>
  26. class BinderHolder
  27. {
  28.     AbstractBinder<A1> *ptr;
  29.     BinderHolder &operator=(const BinderHolder&);
  30. public:
  31.     template<typename I, typename M>
  32.     BinderHolder(I i, M m)
  33.         : ptr(new Binder<A1,I,M>(i,m))
  34.     {
  35.     }
  36.     BinderHolder(const BinderHolder &rhs)
  37.         : ptr(rhs.ptr->clone())
  38.     {
  39.     }
  40.     ~BinderHolder()
  41.     {
  42.         delete ptr;
  43.     }
  44.     void operator()(A1 a1)
  45.     {
  46.         ptr->call(a1);
  47.     }
  48. };
  49.  
  50. template<typename A1, typename I, typename M>
  51. BinderHolder<A1> my_bind(I i, M m) {
  52.     return BinderHolder<A1>(i, m);
  53. }
  54.  
  55. #include <iostream>
  56.  
  57. struct Foo {
  58.     void x(int i) { std::cout << "Foo " << i << std::endl; }
  59. };
  60.  
  61. struct Bar {
  62.     void y(int i) { std::cout << "Bar " << i << std::endl; }
  63. };
  64.  
  65. int main()
  66. {
  67.     Foo foo;
  68.     Bar bar;
  69.  
  70.     BinderHolder<int> b1 = my_bind<int>(&foo, &Foo::x);
  71.     BinderHolder<int> b2 = my_bind<int>(&bar, &Bar::y);
  72.  
  73.     b1(1);
  74.     b2(2);
  75. }
  76.  
Success #stdin #stdout 0.01s 2816KB
comments (?)
stdin 
Standard input is empty
stdout 
Foo 1
Bar 2
https://ideone.com/JLpAkj
language:
C++ (gcc 8.3)
created:
11 years ago
visibility:
secret

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