stl_function.h

TSP问题的一个类库 有源代码和stl

struct project1st : public _Project1st<_Arg1, _Arg2> {};

template <class _Arg1, class _Arg2>
struct project2nd : public _Project2nd<_Arg1, _Arg2> {};

// constant_void_fun, constant_unary_fun, and constant_binary_fun are
// extensions: they are not part of the standard.  (The same, of course,
// is true of the helper functions constant0, constant1, and constant2.)

template <class _Result>
struct _Constant_void_fun {
  typedef _Result result_type;
  result_type _M_val;

  _Constant_void_fun(const result_type& __v) : _M_val(__v) {}
  const result_type& operator()() const { return _M_val; }
};  

template <class _Result, class _Argument>
struct _Constant_unary_fun {
  typedef _Argument argument_type;
  typedef  _Result  result_type;
  result_type _M_val;

  _Constant_unary_fun(const result_type& __v) : _M_val(__v) {}
  const result_type& operator()(const _Argument&) const { return _M_val; }
};

template <class _Result, class _Arg1, class _Arg2>
struct _Constant_binary_fun {
  typedef  _Arg1   first_argument_type;
  typedef  _Arg2   second_argument_type;
  typedef  _Result result_type;
  _Result _M_val;

  _Constant_binary_fun(const _Result& __v) : _M_val(__v) {}
  const result_type& operator()(const _Arg1&, const _Arg2&) const {
    return _M_val;
  }
};

template <class _Result>
struct constant_void_fun : public _Constant_void_fun<_Result> {
  constant_void_fun(const _Result& __v) : _Constant_void_fun<_Result>(_v) {}
};  


template <class _Result,
          class _Argument __STL_DEPENDENT_DEFAULT_TMPL(_Result)>
struct constant_unary_fun : public _Constant_unary_fun<_Result, _Argument>
{
  constant_unary_fun(const _Result& __v)
    : _Constant_unary_fun<_Result, _Argument>(__v) {}
};


template <class _Result,
          class _Arg1 __STL_DEPENDENT_DEFAULT_TMPL(_Result),
          class _Arg2 __STL_DEPENDENT_DEFAULT_TMPL(_Arg1)>
struct constant_binary_fun
  : public _Constant_binary_fun<_Result, _Arg1, _Arg2>
{
  constant_binary_fun(const _Result& __v)
    : _Constant_binary_fun<_Result, _Arg1, _Arg2>(__v) {}
};

template <class _Result>
inline constant_void_fun<_Result> constant0(const _Result& __val)
{
  return constant_void_fun<_Result>(__val);
}

template <class _Result>
inline constant_unary_fun<_Result,_Result> constant1(const _Result& __val)
{
  return constant_unary_fun<_Result,_Result>(__val);
}

template <class _Result>
inline constant_binary_fun<_Result,_Result,_Result> 
constant2(const _Result& __val)
{
  return constant_binary_fun<_Result,_Result,_Result>(__val);
}

// subtractive_rng is an extension: it is not part of the standard.
// Note: this code assumes that int is 32 bits.
class subtractive_rng : public unary_function<unsigned int, unsigned int> {
private:
  unsigned int _M_table[55];
  size_t _M_index1;
  size_t _M_index2;
public:
  unsigned int operator()(unsigned int __limit) {
    _M_index1 = (_M_index1 + 1) % 55;
    _M_index2 = (_M_index2 + 1) % 55;
    _M_table[_M_index1] = _M_table[_M_index1] - _M_table[_M_index2];
    return _M_table[_M_index1] % __limit;
  }

  void _M_initialize(unsigned int __seed)
  {
    unsigned int __k = 1;
    _M_table[54] = __seed;
    size_t __i;
    for (__i = 0; __i < 54; __i++) {
        size_t __ii = (21 * (__i + 1) % 55) - 1;
        _M_table[__ii] = __k;
        __k = __seed - __k;
        __seed = _M_table[__ii];
    }
    for (int __loop = 0; __loop < 4; __loop++) {
        for (__i = 0; __i < 55; __i++)
            _M_table[__i] = _M_table[__i] - _M_table[(1 + __i + 30) % 55];
    }
    _M_index1 = 0;
    _M_index2 = 31;
  }

  subtractive_rng(unsigned int __seed) { _M_initialize(__seed); }
  subtractive_rng() { _M_initialize(161803398u); }
};


// Adaptor function objects: pointers to member functions.

// There are a total of 16 = 2^4 function objects in this family.
//  (1) Member functions taking no arguments vs member functions taking
//       one argument.
//  (2) Call through pointer vs call through reference.
//  (3) Member function with void return type vs member function with
//      non-void return type.
//  (4) Const vs non-const member function.

// Note that choice (3) is nothing more than a workaround: according
//  to the draft, compilers should handle void and non-void the same way.
//  This feature is not yet widely implemented, though.  You can only use
//  member functions returning void if your compiler supports partial
//  specialization.

// All of this complexity is in the function objects themselves.  You can
//  ignore it by using the helper function mem_fun and mem_fun_ref,
//  which create whichever type of adaptor is appropriate.
//  (mem_fun1 and mem_fun1_ref are no longer part of the C++ standard,
//  but they are provided for backward compatibility.)


template <class _Ret, class _Tp>
class mem_fun_t : public unary_function<_Tp*,_Ret> {
public:
  explicit mem_fun_t(_Ret (_Tp::*__pf)()) : _M_f(__pf) {}
  _Ret operator()(_Tp* __p) const { return (__p->*_M_f)(); }
private:
  _Ret (_Tp::*_M_f)();
};

template <class _Ret, class _Tp>
class const_mem_fun_t : public unary_function<const _Tp*,_Ret> {
public:
  explicit const_mem_fun_t(_Ret (_Tp::*__pf)() const) : _M_f(__pf) {}
  _Ret operator()(const _Tp* __p) const { return (__p->*_M_f)(); }
private:
  _Ret (_Tp::*_M_f)() const;
};


template <class _Ret, class _Tp>
class mem_fun_ref_t : public unary_function<_Tp,_Ret> {
public:
  explicit mem_fun_ref_t(_Ret (_Tp::*__pf)()) : _M_f(__pf) {}
  _Ret operator()(_Tp& __r) const { return (__r.*_M_f)(); }
private:
  _Ret (_Tp::*_M_f)();
};

template <class _Ret, class _Tp>
class const_mem_fun_ref_t : public unary_function<_Tp,_Ret> {
public:
  explicit const_mem_fun_ref_t(_Ret (_Tp::*__pf)() const) : _M_f(__pf) {}
  _Ret operator()(const _Tp& __r) const { return (__r.*_M_f)(); }
private:
  _Ret (_Tp::*_M_f)() const;
};

template <class _Ret, class _Tp, class _Arg>
class mem_fun1_t : public binary_function<_Tp*,_Arg,_Ret> {
public:
  explicit mem_fun1_t(_Ret (_Tp::*__pf)(_Arg)) : _M_f(__pf) {}
  _Ret operator()(_Tp* __p, _Arg __x) const { return (__p->*_M_f)(__x); }
private:
  _Ret (_Tp::*_M_f)(_Arg);
};

template <class _Ret, class _Tp, class _Arg>
class const_mem_fun1_t : public binary_function<const _Tp*,_Arg,_Ret> {
public:
  explicit const_mem_fun1_t(_Ret (_Tp::*__pf)(_Arg) const) : _M_f(__pf) {}
  _Ret operator()(const _Tp* __p, _Arg __x) const
    { return (__p->*_M_f)(__x); }
private:
  _Ret (_Tp::*_M_f)(_Arg) const;
};

template <class _Ret, class _Tp, class _Arg>
class mem_fun1_ref_t : public binary_function<_Tp,_Arg,_Ret> {
public:
  explicit mem_fun1_ref_t(_Ret (_Tp::*__pf)(_Arg)) : _M_f(__pf) {}
  _Ret operator()(_Tp& __r, _Arg __x) const { return (__r.*_M_f)(__x); }
private:
  _Ret (_Tp::*_M_f)(_Arg);
};

template <class _Ret, class _Tp, class _Arg>
class const_mem_fun1_ref_t : public binary_function<_Tp,_Arg,_Ret> {
public:
  explicit const_mem_fun1_ref_t(_Ret (_Tp::*__pf)(_Arg) const) : _M_f(__pf) {}
  _Ret operator()(const _Tp& __r, _Arg __x) const { return (__r.*_M_f)(__x); }
private:
  _Ret (_Tp::*_M_f)(_Arg) const;
};

#ifdef __STL_CLASS_PARTIAL_SPECIALIZATION

template <class _Tp>
class mem_fun_t<void, _Tp> : public unary_function<_Tp*,void> {
public:
  explicit mem_fun_t(void (_Tp::*__pf)()) : _M_f(__pf) {}
  void operator()(_Tp* __p) const { (__p->*_M_f)(); }
private:
  void (_Tp::*_M_f)();
};

template <class _Tp>
class const_mem_fun_t<void, _Tp> : public unary_function<const _Tp*,void> {
public:
  explicit const_mem_fun_t(void (_Tp::*__pf)() const) : _M_f(__pf) {}
  void operator()(const _Tp* __p) const { (__p->*_M_f)(); }
private:
  void (_Tp::*_M_f)() const;
};

template <class _Tp>
class mem_fun_ref_t<void, _Tp> : public unary_function<_Tp,void> {
public:
  explicit mem_fun_ref_t(void (_Tp::*__pf)()) : _M_f(__pf) {}
  void operator()(_Tp& __r) const { (__r.*_M_f)(); }
private:
  void (_Tp::*_M_f)();
};

template <class _Tp>
class const_mem_fun_ref_t<void, _Tp> : public unary_function<_Tp,void> {
public:
  explicit const_mem_fun_ref_t(void (_Tp::*__pf)() const) : _M_f(__pf) {}
  void operator()(const _Tp& __r) const { (__r.*_M_f)(); }
private:
  void (_Tp::*_M_f)() const;
};

template <class _Tp, class _Arg>
class mem_fun1_t<void, _Tp, _Arg> : public binary_function<_Tp*,_Arg,void> {
public:
  explicit mem_fun1_t(void (_Tp::*__pf)(_Arg)) : _M_f(__pf) {}
  void operator()(_Tp* __p, _Arg __x) const { (__p->*_M_f)(__x); }
private:
  void (_Tp::*_M_f)(_Arg);
};

template <class _Tp, class _Arg>
class const_mem_fun1_t<void, _Tp, _Arg> 
  : public binary_function<const _Tp*,_Arg,void> {
public:
  explicit const_mem_fun1_t(void (_Tp::*__pf)(_Arg) const) : _M_f(__pf) {}
  void operator()(const _Tp* __p, _Arg __x) const { (__p->*_M_f)(__x); }
private:
  void (_Tp::*_M_f)(_Arg) const;
};

template <class _Tp, class _Arg>
class mem_fun1_ref_t<void, _Tp, _Arg>
  : public binary_function<_Tp,_Arg,void> {
public:
  explicit mem_fun1_ref_t(void (_Tp::*__pf)(_Arg)) : _M_f(__pf) {}
  void operator()(_Tp& __r, _Arg __x) const { (__r.*_M_f)(__x); }
private:
  void (_Tp::*_M_f)(_Arg);
};

template <class _Tp, class _Arg>
class const_mem_fun1_ref_t<void, _Tp, _Arg>
  : public binary_function<_Tp,_Arg,void> {
public:
  explicit const_mem_fun1_ref_t(void (_Tp::*__pf)(_Arg) const) : _M_f(__pf) {}
  void operator()(const _Tp& __r, _Arg __x) const { (__r.*_M_f)(__x); }
private:
  void (_Tp::*_M_f)(_Arg) const;
};

#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */

// Mem_fun adaptor helper functions.  There are only two:
//  mem_fun and mem_fun_ref.  (mem_fun1 and mem_fun1_ref 
//  are provided for backward compatibility, but they are no longer
//  part of the C++ standard.)

template <class _Ret, class _Tp>
inline mem_fun_t<_Ret,_Tp> mem_fun(_Ret (_Tp::*__f)())
  { return mem_fun_t<_Ret,_Tp>(__f); }

template <class _Ret, class _Tp>
inline const_mem_fun_t<_Ret,_Tp> mem_fun(_Ret (_Tp::*__f)() const)
  { return const_mem_fun_t<_Ret,_Tp>(__f); }

template <class _Ret, class _Tp>
inline mem_fun_ref_t<_Ret,_Tp> mem_fun_ref(_Ret (_Tp::*__f)()) 
  { return mem_fun_ref_t<_Ret,_Tp>(__f); }

template <class _Ret, class _Tp>
inline const_mem_fun_ref_t<_Ret,_Tp> mem_fun_ref(_Ret (_Tp::*__f)() const)
  { return const_mem_fun_ref_t<_Ret,_Tp>(__f); }

template <class _Ret, class _Tp, class _Arg>
inline mem_fun1_t<_Ret,_Tp,_Arg> mem_fun(_Ret (_Tp::*__f)(_Arg))
  { return mem_fun1_t<_Ret,_Tp,_Arg>(__f); }

template <class _Ret, class _Tp, class _Arg>
inline const_mem_fun1_t<_Ret,_Tp,_Arg> mem_fun(_Ret (_Tp::*__f)(_Arg) const)
  { return const_mem_fun1_t<_Ret,_Tp,_Arg>(__f); }

template <class _Ret, class _Tp, class _Arg>
inline mem_fun1_ref_t<_Ret,_Tp,_Arg> mem_fun_ref(_Ret (_Tp::*__f)(_Arg))
  { return mem_fun1_ref_t<_Ret,_Tp,_Arg>(__f); }

template <class _Ret, class _Tp, class _Arg>
inline const_mem_fun1_ref_t<_Ret,_Tp,_Arg>
mem_fun_ref(_Ret (_Tp::*__f)(_Arg) const)
  { return const_mem_fun1_ref_t<_Ret,_Tp,_Arg>(__f); }

template <class _Ret, class _Tp, class _Arg>
inline mem_fun1_t<_Ret,_Tp,_Arg> mem_fun1(_Ret (_Tp::*__f)(_Arg))
  { return mem_fun1_t<_Ret,_Tp,_Arg>(__f); }

template <class _Ret, class _Tp, class _Arg>
inline const_mem_fun1_t<_Ret,_Tp,_Arg> mem_fun1(_Ret (_Tp::*__f)(_Arg) const)
  { return const_mem_fun1_t<_Ret,_Tp,_Arg>(__f); }

template <class _Ret, class _Tp, class _Arg>
inline mem_fun1_ref_t<_Ret,_Tp,_Arg> mem_fun1_ref(_Ret (_Tp::*__f)(_Arg))
  { return mem_fun1_ref_t<_Ret,_Tp,_Arg>(__f); }

template <class _Ret, class _Tp, class _Arg>
inline const_mem_fun1_ref_t<_Ret,_Tp,_Arg>
mem_fun1_ref(_Ret (_Tp::*__f)(_Arg) const)
  { return const_mem_fun1_ref_t<_Ret,_Tp,_Arg>(__f); }

__STL_END_NAMESPACE

#endif /* __SGI_STL_INTERNAL_FUNCTION_H */

// Local Variables:
// mode:C++
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