stl_function.h

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// Functor implementations -*- C++ -*-

// Copyright (C) 2001, 2002, 2004, 2005 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.

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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

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// USA.

// As a special exception, you may use this file as part of a free software
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// invalidate any other reasons why the executable file might be covered by
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/*
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Hewlett-Packard Company makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 *
 * Copyright (c) 1996-1998
 * Silicon Graphics Computer Systems, Inc.
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Silicon Graphics makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 */

#ifndef _FUNCTION_H
#define _FUNCTION_H 1

namespace std
{
  // 20.3.1 base classes
  template <class _Arg, class _Result>
    struct unary_function
    {
      typedef _Arg argument_type;   


      typedef _Result result_type;  
    };

  template <class _Arg1, class _Arg2, class _Result>
    struct binary_function
    {
      typedef _Arg1 first_argument_type;   


      typedef _Arg2 second_argument_type;  
      typedef _Result result_type;         
    };
  // 20.3.2 arithmetic

  template <class _Tp>
    struct plus : public binary_function<_Tp, _Tp, _Tp>
    {
      _Tp
      operator()(const _Tp& __x, const _Tp& __y) const
      { return __x + __y; }
    };

  template <class _Tp>
    struct minus : public binary_function<_Tp, _Tp, _Tp>
    {
      _Tp
      operator()(const _Tp& __x, const _Tp& __y) const
      { return __x - __y; }
    };

  template <class _Tp>
    struct multiplies : public binary_function<_Tp, _Tp, _Tp>
    {
      _Tp
      operator()(const _Tp& __x, const _Tp& __y) const
      { return __x * __y; }
    };

  template <class _Tp>
    struct divides : public binary_function<_Tp, _Tp, _Tp>
    {
      _Tp
      operator()(const _Tp& __x, const _Tp& __y) const
      { return __x / __y; }
    };

  template <class _Tp>
    struct modulus : public binary_function<_Tp, _Tp, _Tp>
    {
      _Tp
      operator()(const _Tp& __x, const _Tp& __y) const
      { return __x % __y; }
    };

  template <class _Tp>
    struct negate : public unary_function<_Tp, _Tp>
    {
      _Tp
      operator()(const _Tp& __x) const
      { return -__x; }
    };
  // 20.3.3 comparisons

  template <class _Tp>
    struct equal_to : public binary_function<_Tp, _Tp, bool>
    {
      bool
      operator()(const _Tp& __x, const _Tp& __y) const
      { return __x == __y; }
    };

  template <class _Tp>
    struct not_equal_to : public binary_function<_Tp, _Tp, bool>
    {
      bool
      operator()(const _Tp& __x, const _Tp& __y) const
      { return __x != __y; }
    };

  template <class _Tp>
    struct greater : public binary_function<_Tp, _Tp, bool>
    {
      bool
      operator()(const _Tp& __x, const _Tp& __y) const
      { return __x > __y; }
    };

  template <class _Tp>
    struct less : public binary_function<_Tp, _Tp, bool>
    {
      bool
      operator()(const _Tp& __x, const _Tp& __y) const
      { return __x < __y; }
    };

  template <class _Tp>
    struct greater_equal : public binary_function<_Tp, _Tp, bool>
    {
      bool
      operator()(const _Tp& __x, const _Tp& __y) const
      { return __x >= __y; }
    };

  template <class _Tp>
    struct less_equal : public binary_function<_Tp, _Tp, bool>
    {
      bool
      operator()(const _Tp& __x, const _Tp& __y) const
      { return __x <= __y; }
    };
  // 20.3.4 logical operations

  template <class _Tp>
    struct logical_and : public binary_function<_Tp, _Tp, bool>
    {
      bool
      operator()(const _Tp& __x, const _Tp& __y) const
      { return __x && __y; }
    };

  template <class _Tp>
    struct logical_or : public binary_function<_Tp, _Tp, bool>
    {
      bool
      operator()(const _Tp& __x, const _Tp& __y) const
      { return __x || __y; }
    };

  template <class _Tp>
    struct logical_not : public unary_function<_Tp, bool>
    {
      bool
      operator()(const _Tp& __x) const
      { return !__x; }
    };
  // 20.3.5 negators

  template <class _Predicate>
    class unary_negate
    : public unary_function<typename _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 _Predicate::first_argument_type,
                 typename _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); }
  // 20.3.6 binders

  template <class _Operation>
    class binder1st
    : public unary_function<typename _Operation::second_argument_type,
                typename _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); }

      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // 109.  Missing binders for non-const sequence elements
      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 _Operation::first_argument_type,
                typename _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); }

      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // 109.  Missing binders for non-const sequence elements
      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));
    }
  // 20.3.7 adaptors pointers functions

  template <class _Arg, class _Result>
    class pointer_to_unary_function : public unary_function<_Arg, _Result>
    {
    protected:
      _Result (*_M_ptr)(_Arg);
    public:
      pointer_to_unary_function() {}

      explicit
      pointer_to_unary_function(_Result (*__x)(_Arg))
      : _M_ptr(__x) {}

      _Result
      operator()(_Arg __x) const
      { return _M_ptr(__x); }
    };

  template <class _Arg, class _Result>
    inline pointer_to_unary_function<_Arg, _Result>
    ptr_fun(_Result (*__x)(_Arg))
    { return pointer_to_unary_function<_Arg, _Result>(__x); }

  template <class _Arg1, class _Arg2, class _Result>
    class pointer_to_binary_function
    : public binary_function<_Arg1, _Arg2, _Result>
    {
    protected:
      _Result (*_M_ptr)(_Arg1, _Arg2);
    public:
      pointer_to_binary_function() {}

      explicit
      pointer_to_binary_function(_Result (*__x)(_Arg1, _Arg2))
      : _M_ptr(__x) {}

      _Result
      operator()(_Arg1 __x, _Arg2 __y) const
      { return _M_ptr(__x, __y); }
    };

  template <class _Arg1, class _Arg2, class _Result>
    inline pointer_to_binary_function<_Arg1, _Arg2, _Result>
    ptr_fun(_Result (*__x)(_Arg1, _Arg2))
    { return pointer_to_binary_function<_Arg1, _Arg2, _Result>(__x); }
  template <class _Tp>
    struct _Identity : public unary_function<_Tp,_Tp>
    {
      _Tp&
      operator()(_Tp& __x) const
      { return __x; }

      const _Tp&
      operator()(const _Tp& __x) const
      { return __x; }
    };

  template <class _Pair>
    struct _Select1st : public unary_function<_Pair,
                          typename _Pair::first_type>
    {
      typename _Pair::first_type&
      operator()(_Pair& __x) const
      { return __x.first; }

      const typename _Pair::first_type&
      operator()(const _Pair& __x) const
      { return __x.first; }
    };

  template <class _Pair>
    struct _Select2nd : public unary_function<_Pair,
                          typename _Pair::second_type>
    {
      typename _Pair::second_type&
      operator()(_Pair& __x) const
      { return __x.second; }

      const typename _Pair::second_type&
      operator()(const _Pair& __x) const
      { return __x.second; }
    };

  // 20.3.8 adaptors pointers members

  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;
    };

  // Mem_fun adaptor helper functions.  There are only two:
  // mem_fun and mem_fun_ref.
  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); }

} // namespace std

#endif /* _FUNCTION_H */

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