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// TR1 functional header -*- C++ -*-

// Copyright (C) 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.

// This library is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along

// with this library; see the file COPYING.  If not, write to the Free

// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,

// USA.

// As a special exception, you may use this file as part of a free software

// library without restriction.  Specifically, if other files instantiate

// templates or use macros or inline functions from this file, or you compile

// this file and link it with other files to produce an executable, this

// file does not by itself cause the resulting executable to be covered by

// the GNU General Public License.  This exception does not however

// invalidate any other reasons why the executable file might be covered by

// the GNU General Public License.

/** @file

 *  This is a TR1 C++ Library header.

 */

#ifndef _TR1_FUNCTIONAL

#define _TR1_FUNCTIONAL 1

#pragma GCC system_header

#include "../functional"

#include 

#include 

#include 

#include                // for std::tr1::hash

#include               // for std::abort

#include                 // for std::frexp

#include 

namespace std

{

namespace tr1

{

  template

    class _Mem_fn;

  /**

   *  @if maint

   *  Actual implementation of _Has_result_type, which uses SFINAE to

   *  determine if the type _Tp has a publicly-accessible member type

   *  result_type.

   *  @endif

  */

  template

    class _Has_result_type_helper : __sfinae_types

    {

      template

      struct _Wrap_type

      { };

      template

        static __one __test(_Wrap_type*);

      template

        static __two __test(...);

    public:

      static const bool value = sizeof(__test<_Tp>(0)) == 1;

    };

  template

    struct _Has_result_type

       : integral_constant<

           bool,

           _Has_result_type_helper::type>::value>

    { };

  /**

   *  @if maint

   *  If we have found a result_type, extract it.

   *  @endif

  */

  template

    struct _Maybe_get_result_type

    { };

  template

    struct _Maybe_get_result_type

    {

      typedef typename _Functor::result_type result_type;

    };

  /**

   *  @if maint

   *  Base class for any function object that has a weak result type, as

   *  defined in 3.3/3 of TR1.

   *  @endif

  */

  template

    struct _Weak_result_type_impl

      : _Maybe_get_result_type<_Has_result_type<_Functor>::value, _Functor>

    {

    };

  /**

   *  @if maint

   *  Strip top-level cv-qualifiers from the function object and let

   *  _Weak_result_type_impl perform the real work.

   *  @endif

  */

  template

    struct _Weak_result_type

    : _Weak_result_type_impl::type>

    {

    };

  template

    class result_of;

  /**

   *  @if maint

   *  Actual implementation of result_of. When _Has_result_type is

   *  true, gets its result from _Weak_result_type. Otherwise, uses

   *  the function object's member template result to extract the

   *  result type.

   *  @endif

  */

  template

    struct _Result_of_impl;

  // Handle member data pointers using _Mem_fn's logic

  template

    struct _Result_of_impl

    {

      typedef typename _Mem_fn<_Res _Class::*>

                ::template _Result_type<_T1>::type type;

    };

  /**

   *  @if maint

   *  Determines if the type _Tp derives from unary_function.

   *  @endif

  */

  template

    struct _Derives_from_unary_function : __sfinae_types

    {

    private:

      template

        static __one __test(const volatile unary_function<_T1, _Res>*);

      // It's tempting to change "..." to const volatile void*, but

      // that fails when _Tp is a function type.

      static __two __test(...);

    public:

      static const bool value = sizeof(__test((_Tp*)0)) == 1;

    };

  /**

   *  @if maint

   *  Determines if the type _Tp derives from binary_function.

   *  @endif

  */

  template

    struct _Derives_from_binary_function : __sfinae_types

    {

    private:

      template

        static __one __test(const volatile binary_function<_T1, _T2, _Res>*);

      // It's tempting to change "..." to const volatile void*, but

      // that fails when _Tp is a function type.

      static __two __test(...);

    public:

      static const bool value = sizeof(__test((_Tp*)0)) == 1;

    };

  /**

   *  @if maint

   *  Turns a function type into a function pointer type

   *  @endif

  */

  template::value>

    struct _Function_to_function_pointer

    {

      typedef _Tp type;

    };

  template

    struct _Function_to_function_pointer<_Tp, true>

    {

      typedef _Tp* type;

    };

  /**

   *  @if maint

   *  Knowing which of unary_function and binary_function _Tp derives

   *  from, derives from the same and ensures that reference_wrapper

   *  will have a weak result type. See cases below.

   *  @endif

   */

  template

    struct _Reference_wrapper_base_impl;

  // Not a unary_function or binary_function, so try a weak result type

  template

    struct _Reference_wrapper_base_impl

      : _Weak_result_type<_Tp>

    { };

  // unary_function but not binary_function

  template

    struct _Reference_wrapper_base_impl

      : unary_function

                       typename _Tp::result_type>

    { };

  // binary_function but not unary_function

  template

    struct _Reference_wrapper_base_impl

      : binary_function

                        typename _Tp::second_argument_type,

                        typename _Tp::result_type>

    { };

  // both unary_function and binary_function. import result_type to

  // avoid conflicts.

   template

    struct _Reference_wrapper_base_impl

      : unary_function

                       typename _Tp::result_type>,

        binary_function

                        typename _Tp::second_argument_type,

                        typename _Tp::result_type>

    {

      typedef typename _Tp::result_type result_type;

    };

  /**

   *  @if maint

   *  Derives from unary_function or binary_function when it

   *  can. Specializations handle all of the easy cases. The primary

   *  template determines what to do with a class type, which may

   *  derive from both unary_function and binary_function.

   *  @endif

  */

  template

    struct _Reference_wrapper_base

      : _Reference_wrapper_base_impl<

          _Derives_from_unary_function<_Tp>::value,

          _Derives_from_binary_function<_Tp>::value,

          _Tp>

    { };

  // - a function type (unary)

  template

    struct _Reference_wrapper_base<_Res(_T1)>

      : unary_function<_T1, _Res>

    { };

  // - a function type (binary)

  template

    struct _Reference_wrapper_base<_Res(_T1, _T2)>

      : binary_function<_T1, _T2, _Res>

    { };

  // - a function pointer type (unary)

  template

    struct _Reference_wrapper_base<_Res(*)(_T1)>

      : unary_function<_T1, _Res>

    { };

  // - a function pointer type (binary)

  template

    struct _Reference_wrapper_base<_Res(*)(_T1, _T2)>

      : binary_function<_T1, _T2, _Res>

    { };

  // - a pointer to member function type (unary, no qualifiers)

  template

    struct _Reference_wrapper_base<_Res (_T1::*)()>

      : unary_function<_T1*, _Res>

    { };

  // - a pointer to member function type (binary, no qualifiers)

  template

    struct _Reference_wrapper_base<_Res (_T1::*)(_T2)>

      : binary_function<_T1*, _T2, _Res>

    { };

  // - a pointer to member function type (unary, const)

  template

    struct _Reference_wrapper_base<_Res (_T1::*)() const>

      : unary_function

    { };

  // - a pointer to member function type (binary, const)

  template

    struct _Reference_wrapper_base<_Res (_T1::*)(_T2) const>

      : binary_function

    { };

  // - a pointer to member function type (unary, volatile)

  template

    struct _Reference_wrapper_base<_Res (_T1::*)() volatile>

      : unary_function

    { };

  // - a pointer to member function type (binary, volatile)

  template

    struct _Reference_wrapper_base<_Res (_T1::*)(_T2) volatile>

      : binary_function

    { };

  // - a pointer to member function type (unary, const volatile)

  template

    struct _Reference_wrapper_base<_Res (_T1::*)() const volatile>

      : unary_function

    { };

  // - a pointer to member function type (binary, const volatile)

  template

    struct _Reference_wrapper_base<_Res (_T1::*)(_T2) const volatile>

      : binary_function

    { };

  template

    class reference_wrapper

      : public _Reference_wrapper_base::type>

    {

      // If _Tp is a function type, we can't form result_of<_Tp(...)>,

      // so turn it into a function pointer type.

      typedef typename _Function_to_function_pointer<_Tp>::type

        _M_func_type;

      _Tp* _M_data;

    public:

      typedef _Tp type;

      explicit reference_wrapper(_Tp& __indata): _M_data(&__indata)

      { }

      reference_wrapper(const reference_wrapper<_Tp>& __inref):

      _M_data(__inref._M_data)

      { }

      reference_wrapper&

      operator=(const reference_wrapper<_Tp>& __inref)

      {

        _M_data = __inref._M_data;

        return *this;

      }

      operator _Tp&() const

      { return this->get(); }

      _Tp&

      get() const

      { return *_M_data; }

#define _GLIBCXX_REPEAT_HEADER 

#include 

#undef _GLIBCXX_REPEAT_HEADER

    };

  // Denotes a reference should be taken to a variable.

  template

    inline reference_wrapper<_Tp>

    ref(_Tp& __t)

    { return reference_wrapper<_Tp>(__t); }

  // Denotes a const reference should be taken to a variable.

  template

    inline reference_wrapper

    cref(const _Tp& __t)

    { return reference_wrapper(__t); }

  template

    inline reference_wrapper<_Tp>

    ref(reference_wrapper<_Tp> __t)

    { return ref(__t.get()); }

  template

    inline reference_wrapper

    cref(reference_wrapper<_Tp> __t)

    { return cref(__t.get()); }

   template

     struct _Mem_fn_const_or_non

     {

       typedef const _Tp& type;

     };

    template

      struct _Mem_fn_const_or_non<_Tp, false>

      {

        typedef _Tp& type;

      };

  template

  class _Mem_fn<_Res _Class::*>

  {

    // This bit of genius is due to Peter Dimov, improved slightly by

    // Douglas Gregor.

    template

      _Res&

      _M_call(_Tp& __object, _Class *) const

      { return __object.*__pm; }

    template

      _Res&

      _M_call(_Tp& __object, _Up * const *) const

      { return (*__object).*__pm; }

    template

      const _Res&

      _M_call(_Tp& __object, const _Up * const *) const

      { return (*__object).*__pm; }

    template

      const _Res&

      _M_call(_Tp& __object, const _Class *) const

      { return __object.*__pm; }

    template

      const _Res&

      _M_call(_Tp& __ptr, const volatile void*) const

      { return (*__ptr).*__pm; }

    template static _Tp& __get_ref();

    template

      static __sfinae_types::__one __check_const(_Tp&, _Class*);

    template

      static __sfinae_types::__one __check_const(_Tp&, _Up * const *);

    template

      static __sfinae_types::__two __check_const(_Tp&, const _Up * const *);

    template

      static __sfinae_types::__two __check_const(_Tp&, const _Class*);

    template

      static __sfinae_types::__two __check_const(_Tp&, const volatile void*);

  public:

    template

      struct _Result_type

        : _Mem_fn_const_or_non<

            _Res,

            (sizeof(__sfinae_types::__two)

             == sizeof(__check_const<_Tp>(__get_ref<_Tp>(), (_Tp*)0)))>

      { };

    template

      struct result;

    template

      struct result<_CVMem(_Tp)>

        : public _Result_type<_Tp> { };

    template

      struct result<_CVMem(_Tp&)>

        : public _Result_type<_Tp> { };

    explicit _Mem_fn(_Res _Class::*__pm) : __pm(__pm) { }

    // Handle objects

    _Res&       operator()(_Class& __object)       const

    { return __object.*__pm; }

    const _Res& operator()(const _Class& __object) const

    { return __object.*__pm; }

    // Handle pointers

    _Res&       operator()(_Class* __object)       const

    { return __object->*__pm; }

    const _Res&

    operator()(const _Class* __object) const

    { return __object->*__pm; }

    // Handle smart pointers and derived

    template

      typename _Result_type<_Tp>::type

      operator()(_Tp& __unknown) const

      { return _M_call(__unknown, &__unknown); }

  private:

    _Res _Class::*__pm;

  };

  /**

   *  @brief Returns a function object that forwards to the member

   *  pointer @a pm.

   */

  template

    inline _Mem_fn<_Tp _Class::*>

    mem_fn(_Tp _Class::* __pm)

    {

      return _Mem_fn<_Tp _Class::*>(__pm);

    }

  /**

   *  @brief Determines if the given type _Tp is a function object

   *  should be treated as a subexpression when evaluating calls to

   *  function objects returned by bind(). [TR1 3.6.1]

   */

  template

    struct is_bind_expression

    {

      static const bool value = false;

    };

  /**

   *  @brief Determines if the given type _Tp is a placeholder in a

   *  bind() expression and, if so, which placeholder it is. [TR1 3.6.2]

   */

  template

    struct is_placeholder

    {

      static const int value = 0;

    };

  /**

   *  @if maint

   *  The type of placeholder objects defined by libstdc++.

   *  @endif

   */

  template struct _Placeholder { };

  /**

   *  @if maint

   *  Partial specialization of is_placeholder that provides the placeholder

   *  number for the placeholder objects defined by libstdc++.

   *  @endif

   */

  template

    struct is_placeholder<_Placeholder<_Num> >

    {

      static const int value = _Num;

    };

  /**

   *  @if maint

   *  Maps an argument to bind() into an actual argument to the bound

   *  function object [TR1 3.6.3/5]. Only the first parameter should

   *  be specified: the rest are used to determine among the various

   *  implementations. Note that, although this class is a function

   *  object, isn't not entirely normal because it takes only two

   *  parameters regardless of the number of parameters passed to the

   *  bind expression. The first parameter is the bound argument and

   *  the second parameter is a tuple containing references to the

   *  rest of the arguments.

   *  @endif

   */

  template

           bool _IsBindExp = is_bind_expression<_Arg>::value,

           bool _IsPlaceholder = (is_placeholder<_Arg>::value > 0)>

    class _Mu;

  /**

   *  @if maint

   *  If the argument is reference_wrapper<_Tp>, returns the

   *  underlying reference. [TR1 3.6.3/5 bullet 1]

   *  @endif

   */

  template

    class _Mu, false, false>

    {

    public:

      typedef _Tp& result_type;

      /* Note: This won't actually work for const volatile

       * reference_wrappers, because reference_wrapper::get() is const

       * but not volatile-qualified. This might be a defect in the TR.

       */

      template

      result_type

      operator()(_CVRef& __arg, const _Tuple&) const volatile

      { return __arg.get(); }

    };

  /**

   *  @if maint

   *  If the argument is a bind expression, we invoke the underlying

   *  function object with the same cv-qualifiers as we are given and

   *  pass along all of our arguments (unwrapped). [TR1 3.6.3/5 bullet 2]

   *  @endif

   */

  template

    class _Mu<_Arg, true, false>

    {

    public:

      template class result;

#define _GLIBCXX_REPEAT_HEADER 

#  include 

#undef _GLIBCXX_REPEAT_HEADER

    };

  /**

   *  @if maint

   *  If the argument is a placeholder for the Nth argument, returns

   *  a reference to the Nth argument to the bind function object.

   *  [TR1 3.6.3/5 bullet 3]

   *  @endif

   */

  template

    class _Mu<_Arg, false, true>

    {

    public:

      template class result;

      template

      class result<_CVMu(_CVArg, _Tuple)>

      {

        // Add a reference, if it hasn't already been done for us.

        // This allows us to be a little bit sloppy in constructing

        // the tuple that we pass to result_of<...>.

        typedef typename tuple_element<(is_placeholder<_Arg>::value - 1),

                                       _Tuple>::type __base_type;

      public:

        typedef typename add_reference<__base_type>::type type;

      };

      template

      typename result<_Mu(_Arg, _Tuple)>::type

      operator()(const volatile _Arg&, const _Tuple& __tuple) const volatile

      {

        return ::std::tr1::get<(is_placeholder<_Arg>::value - 1)>(__tuple);

      }

    };

  /**

   *  @if maint

   *  If the argument is just a value, returns a reference to that

   *  value. The cv-qualifiers on the reference are the same as the

   *  cv-qualifiers on the _Mu object. [TR1 3.6.3/5 bullet 4]

   *  @endif

   */

  template

    class _Mu<_Arg, false, false>

    {

    public:

      template struct result;

      template

      struct result<_CVMu(_CVArg, _Tuple)>

      {

        typedef typename add_reference<_CVArg>::type type;

      };

      // Pick up the cv-qualifiers of the argument

      template

      _CVArg& operator()(_CVArg& __arg, const _Tuple&) const volatile

      { return __arg; }

    };

  /**

   *  @if maint

   *  Maps member pointers into instances of _Mem_fn but leaves all

   *  other function objects untouched. Used by tr1::bind(). The

   *  primary template handles the non--member-pointer case.

   *  @endif

   */

  template

    struct _Maybe_wrap_member_pointer

    {

      typedef _Tp type;

      static const _Tp& __do_wrap(const _Tp& __x) { return __x; }

    };

  /**

   *  @if maint

   *  Maps member pointers into instances of _Mem_fn but leaves all

   *  other function objects untouched. Used by tr1::bind(). This

   *  partial specialization handles the member pointer case.

   *  @endif

   */

  template

    struct _Maybe_wrap_member_pointer<_Tp _Class::*>

    {

      typedef _Mem_fn<_Tp _Class::*> type;

      static type __do_wrap(_Tp _Class::* __pm) { return type(__pm); }

    };

  /**

   *  @if maint

   *  Type of the function object returned from bind().

   *  @endif

   */

   template

     struct _Bind;

  /**

   *  @if maint

   *  Type of the function object returned from bind().

   *  @endif

   */

   template

     struct _Bind_result;

  /**

   *  @if maint

   *  Class template _Bind is always a bind expression.

   *  @endif

   */

   template

    struct is_bind_expression<_Bind<_Signature> >

    {

      static const bool value = true;

    };

  /**

   *  @if maint

   *  Class template _Bind_result is always a bind expression.

   *  @endif

   */

   template

   struct is_bind_expression<_Bind_result<_Result, _Signature> >

    {

      static const bool value = true;

    };

  /**

   *  @brief Exception class thrown when class template function's

   *  operator() is called with an empty target.

   *

   */

  class bad_function_call : public std::exception { };

  /**

   *  @if maint

   *  The integral constant expression 0 can be converted into a

   *  pointer to this type. It is used by the function template to

   *  accept NULL pointers.

   *  @endif

   */

  struct _M_clear_type;

  /**

   *  @if maint

   *  Trait identifying "location-invariant" types, meaning that the

   *  address of the object (or any of its members) will not escape.

   *  Also implies a trivial copy constructor and assignment operator.

   *   @endif

   */

  template

    struct __is_location_invariant

    : integral_constant

                        (is_pointer<_Tp>::value

                         || is_member_pointer<_Tp>::value)>

    {

    };

  class _Undefined_class;

  union _Nocopy_types

  {

    void*       _M_object;

    const void* _M_const_object;

    void (*_M_function_pointer)();

    void (_Undefined_class::*_M_member_pointer)();

  };

  union _Any_data {

    void*       _M_access()       { return &_M_pod_data[0]; }

    const void* _M_access() const { return &_M_pod_data[0]; }

    template _Tp& _M_access()

    { return *static_cast<_Tp*>(_M_access()); }

    template const _Tp& _M_access() const

    { return *static_cast(_M_access()); }

    _Nocopy_types _M_unused;

    char _M_pod_data[sizeof(_Nocopy_types)];

  };

  enum _Manager_operation

  {

    __get_type_info,

    __get_functor_ptr,

    __clone_functor,

    __destroy_functor

  };

  /* Simple type wrapper that helps avoid annoying const problems

     when casting between void pointers and pointers-to-pointers. */

  template

    struct _Simple_type_wrapper

    {

      _Simple_type_wrapper(_Tp __value) : __value(__value) { }

      _Tp __value;

    };

  template

    struct __is_location_invariant<_Simple_type_wrapper<_Tp> >

      : __is_location_invariant<_Tp>

    {

    };

  // Converts a reference to a function object into a callable

  // function object.

  template

    inline _Functor& __callable_functor(_Functor& __f) { return __f; }

  template

    inline _Mem_fn<_Member _Class::*>

    __callable_functor(_Member _Class::* &__p)

    { return mem_fn(__p); }

  template

    inline _Mem_fn<_Member _Class::*>

    __callable_functor(_Member _Class::* const &__p)

    { return mem_fn(__p); }

  template

    class _Function_handler;

  template

    class function;

  /**

   *  @if maint

   *  Base class of all polymorphic function object wrappers.

   *  @endif

   */

  class _Function_base

  {

  public:

    static const std::size_t _M_max_size = sizeof(_Nocopy_types);

    static const std::size_t _M_max_align = __alignof__(_Nocopy_types);

    template

    class _Base_manager

    {

    protected:

      static const bool __stored_locally =

        (__is_location_invariant<_Functor>::value

         && sizeof(_Functor) <= _M_max_size

         && __alignof__(_Functor) <= _M_max_align

         && (_M_max_align % __alignof__(_Functor) == 0));

      typedef integral_constant _Local_storage;

      // Retrieve a pointer to the function object

      static _Functor* _M_get_pointer(const _Any_data& __source)

      {

        const _Functor* __ptr =

          __stored_locally? &__source._M_access<_Functor>()

          /* have stored a pointer */ : __source._M_access<_Functor*>();

        return const_cast<_Functor*>(__ptr);

      }

      // Clone a location-invariant function object that fits within

      // an _Any_data structure.

      static void

      _M_clone(_Any_data& __dest, const _Any_data& __source, true_type)

      {

        new (__dest._M_access()) _Functor(__source._M_access<_Functor>());

      }

      // Clone a function object that is not location-invariant or

      // that cannot fit into an _Any_data structure.

      static void

      _M_clone(_Any_data& __dest, const _Any_data& __source, false_type)

      {

        __dest._M_access<_Functor*>() =

          new _Functor(*__source._M_access<_Functor*>());

      }

      // Destroying a location-invariant object may still require

      // destruction.

      static void

      _M_destroy(_Any_data& __victim, true_type)

      {

        __victim._M_access<_Functor>().~_Functor();

      }

      // Destroying an object located on the heap.

      static void

      _M_destroy(_Any_data& __victim, false_type)

      {

        delete __victim._M_access<_Functor*>();

      }

    public:

      static bool

      _M_manager(_Any_data& __dest, const _Any_data& __source,

                 _Manager_operation __op)

      {

        switch (__op) {

        case __get_type_info:

          __dest._M_access() = &typeid(_Functor);

          break;

        case __get_functor_ptr:

          __dest._M_access<_Functor*>() = _M_get_pointer(__source);

          break;

        case __clone_functor:

          _M_clone(__dest, __source, _Local_storage());

          break;

        case __destroy_functor:

          _M_destroy(__dest, _Local_storage());

          break;

        }

        return false;

      }