/*
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * Copyright (c) 1996-1998
 * Silicon Graphics Computer Systems, Inc.
 *
 * Copyright (c) 1997
 * Moscow Center for SPARC Technology
 *
 * Copyright (c) 1999 
 * Boris Fomitchev
 *
 * This material is provided "as is", with absolutely no warranty expressed
 * or implied. Any use is at your own risk.
 *
 * Permission to use or copy this software for any purpose is hereby granted 
 * without fee, provided the above notices are retained on all copies.
 * Permission to modify the code and to distribute modified code is granted,
 * provided the above notices are retained, and a notice that the code was
 * modified is included with the above copyright notice.
 *
 */

/* NOTE: This is an internal header file, included by other STL headers.
 *   You should not attempt to use it directly.
 */

#ifndef _STLP_INTERNAL_FUNCTION_H
#define _STLP_INTERNAL_FUNCTION_H

#ifndef _STLP_INTERNAL_FUNCTION_BASE_H
#include <stl/_function_base.h>
#endif

_STLP_BEGIN_NAMESPACE

# ifndef _STLP_NO_EXTENSIONS
// identity_element (not part of the C++ standard).
template <class _Tp> inline _Tp identity_element(plus<_Tp>) {  return _Tp(0); }
template <class _Tp> inline _Tp identity_element(multiplies<_Tp>) { return _Tp(1); }
# endif

#  if defined (_STLP_BASE_TYPEDEF_BUG)
// this workaround is needed for SunPro 4.0.1
// suggested by "Martin Abernethy" <gma@paston.co.uk>:

// We have to introduce the XXary_predicate_aux structures in order to
// access the argument and return types of predicate functions supplied
// as type parameters. SUN C++ 4.0.1 compiler gives errors for template type parameters
// of the form 'name1::name2', where name1 is itself a type parameter.
template <class _Pair>
struct __pair_aux : private _Pair
{
	typedef typename _Pair::first_type first_type;
	typedef typename _Pair::second_type second_type;
};

template <class _Operation>
struct __unary_fun_aux : private _Operation
{
	typedef typename _Operation::argument_type argument_type;
	typedef typename _Operation::result_type result_type;
};

template <class _Operation>
struct __binary_fun_aux  : private _Operation
{
	typedef typename _Operation::first_argument_type first_argument_type;
	typedef typename _Operation::second_argument_type second_argument_type;
	typedef typename _Operation::result_type result_type;
};

#  define __UNARY_ARG(__Operation,__type)  __unary_fun_aux<__Operation>::__type
#  define __BINARY_ARG(__Operation,__type)  __binary_fun_aux<__Operation>::__type
#  define __PAIR_ARG(__Pair,__type)  __pair_aux<__Pair>::__type
# else
#  define __UNARY_ARG(__Operation,__type)  __Operation::__type
#  define __BINARY_ARG(__Operation,__type) __Operation::__type
#  define __PAIR_ARG(__Pair,__type) __Pair::__type
# endif

template <class _Predicate>
class unary_negate : 
    public unary_function<typename __UNARY_ARG(_Predicate,argument_type), bool> {
protected:
  _Predicate _M_pred;
public:
  explicit unary_negate(const _Predicate& __x) : _M_pred(__x) {}
  bool operator()(const typename _Predicate::argument_type& __x) const {
    return !_M_pred(__x);
  }
};

template <class _Predicate>
inline unary_negate<_Predicate> 
not1(const _Predicate& __pred)
{
  return unary_negate<_Predicate>(__pred);
}

template <class _Predicate> 
class binary_negate 
    : public binary_function<typename __BINARY_ARG(_Predicate,first_argument_type),
			     typename __BINARY_ARG(_Predicate,second_argument_type), 
                             bool> {
protected:
  _Predicate _M_pred;
public:
  explicit binary_negate(const _Predicate& __x) : _M_pred(__x) {}
  bool operator()(const typename _Predicate::first_argument_type& __x, 
                  const typename _Predicate::second_argument_type& __y) const
  {
    return !_M_pred(__x, __y); 
  }
};

template <class _Predicate>
inline binary_negate<_Predicate> 
not2(const _Predicate& __pred)
{
  return binary_negate<_Predicate>(__pred);
}

template <class _Operation> 
class binder1st : 
    public unary_function<typename __BINARY_ARG(_Operation,second_argument_type),
                          typename __BINARY_ARG(_Operation,result_type) > {
protected:
  _Operation op;
  typename _Operation::first_argument_type value;
public:
  binder1st(const _Operation& __x,
            const typename _Operation::first_argument_type& __y)
      : op(__x), value(__y) {}

  typename _Operation::result_type
  operator()(const typename _Operation::second_argument_type& __x) const {
    return op(value, __x); 
  }

  typename _Operation::result_type
  operator()(typename _Operation::second_argument_type& __x) const {
    return op(value, __x); 
  }
};

template <class _Operation, class _Tp>
inline binder1st<_Operation> 
bind1st(const _Operation& __fn, const _Tp& __x) 
{
  typedef typename _Operation::first_argument_type _Arg1_type;
  return binder1st<_Operation>(__fn, _Arg1_type(__x));
}

template <class _Operation> 
class binder2nd
  : public unary_function<typename __BINARY_ARG(_Operation,first_argument_type),
                          typename __BINARY_ARG(_Operation,result_type)> {
protected:
  _Operation op;
  typename _Operation::second_argument_type value;
public:
  binder2nd(const _Operation& __x,
            const typename _Operation::second_argument_type& __y) 
      : op(__x), value(__y) {}

  typename _Operation::result_type
  operator()(const typename _Operation::first_argument_type& __x) const {
    return op(__x, value); 
  }

  typename _Operation::result_type
  operator()(typename _Operation::first_argument_type& __x) const {
    return op(__x, value); 
  }
};

template <class _Operation, class _Tp>
inline binder2nd<_Operation> 
bind2nd(const _Operation& __fn, const _Tp& __x) 
{
  typedef typename _Operation::second_argument_type _Arg2_type;
  return binder2nd<_Operation>(__fn, _Arg2_type(__x));
}

# ifndef _STLP_NO_EXTENSIONS
// unary_compose and binary_compose (extensions, not part of the standard).

template <class _Operation1, class _Operation2>
class unary_compose : 
  public unary_function<typename __UNARY_ARG(_Operation2,argument_type),
                        typename __UNARY_ARG(_Operation1,result_type)> {
protected:
  _Operation1 _M_fn1;
  _Operation2 _M_fn2;
public:
  unary_compose(const _Operation1& __x, const _Operation2& __y) 
    : _M_fn1(__x), _M_fn2(__y) {}

  typename _Operation1::result_type
  operator()(const typename _Operation2::argument_type& __x) const {
    return _M_fn1(_M_fn2(__x));
  }

  typename _Operation1::result_type
  operator()(typename _Operation2::argument_type& __x) const {
    return _M_fn1(_M_fn2(__x));
  }
};

template <class _Operation1, class _Operation2>
inline unary_compose<_Operation1,_Operation2> 
compose1(const _Operation1& __fn1, const _Operation2& __fn2)
{
  return unary_compose<_Operation1,_Operation2>(__fn1, __fn2);
}

template <class _Operation1, class _Operation2, class _Operation3>
class binary_compose : 
    public unary_function<typename __UNARY_ARG(_Operation2,argument_type),
                          typename __BINARY_ARG(_Operation1,result_type)> {
protected:
  _Operation1 _M_fn1;
  _Operation2 _M_fn2;
  _Operation3 _M_fn3;
public:
  binary_compose(const _Operation1& __x, const _Operation2& __y, 
                 const _Operation3& __z) 
    : _M_fn1(__x), _M_fn2(__y), _M_fn3(__z) { }

  typename _Operation1::result_type
  operator()(const typename _Operation2::argument_type& __x) const {
    return _M_fn1(_M_fn2(__x), _M_fn3(__x));
  }

  typename _Operation1::result_type
  operator()(typename _Operation2::argument_type& __x) const {
    return _M_fn1(_M_fn2(__x), _M_fn3(__x));
  }
};

template <class _Operation1, class _Operation2, class _Operation3>
inline binary_compose<_Operation1, _Operation2, _Operation3> 
compose2(const _Operation1& __fn1, const _Operation2& __fn2, 
         const _Operation3& __fn3)
{
  return binary_compose<_Operation1,_Operation2,_Operation3>
    (__fn1, __fn2, __fn3);
}

# endif /* _STLP_NO_EXTENSIONS */

# ifndef _STLP_NO_EXTENSIONS

// identity is an extension: it is not part of the standard.
template <class _Tp> struct identity : public _Identity<_Tp> {};
// select1st and select2nd are extensions: they are not part of the standard.
template <class _Pair> struct select1st : public _Select1st<_Pair> {};
template <class _Pair> struct select2nd : public _Select2nd<_Pair> {};

template <class _Arg1, class _Arg2> 
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>
struct constant_void_fun : public _Constant_void_fun<_Result> {
  constant_void_fun(const _Result& __v) : _Constant_void_fun<_Result>(__v) {}
};  

template <class _Result, __DFL_TMPL_PARAM( _Argument , _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, __DFL_TMPL_PARAM( _Arg1 , _Result), __DFL_TMPL_PARAM( _Arg2 , _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<_STLP_UINT32_T, _STLP_UINT32_T> {
private:
  _STLP_UINT32_T _M_table[55];
  _STLP_UINT32_T _M_index1;
  _STLP_UINT32_T _M_index2;
public:
  _STLP_UINT32_T operator()(_STLP_UINT32_T __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(_STLP_UINT32_T __seed)
  {
    _STLP_UINT32_T __k = 1;
    _M_table[54] = __seed;
    _STLP_UINT32_T __i;
    for (__i = 0; __i < 54; __i++) {
        _STLP_UINT32_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(161803398ul); }
};

# endif /* _STLP_NO_EXTENSIONS */

_STLP_END_NAMESPACE

#include <stl/_function_adaptors.h>

#endif /* _STLP_INTERNAL_FUNCTION_H */

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