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functional (93666B)


      1 // -*- C++ -*-
      2 //===------------------------ functional ----------------------------------===//
      3 //
      4 //                     The LLVM Compiler Infrastructure
      5 //
      6 // This file is dual licensed under the MIT and the University of Illinois Open
      7 // Source Licenses. See LICENSE.TXT for details.
      8 //
      9 //===----------------------------------------------------------------------===//
     10 
     11 #ifndef _LIBCPP_FUNCTIONAL
     12 #define _LIBCPP_FUNCTIONAL
     13 
     14 /*
     15     functional synopsis
     16 
     17 namespace std
     18 {
     19 
     20 template <class Arg, class Result>
     21 struct unary_function
     22 {
     23     typedef Arg    argument_type;
     24     typedef Result result_type;
     25 };
     26 
     27 template <class Arg1, class Arg2, class Result>
     28 struct binary_function
     29 {
     30     typedef Arg1   first_argument_type;
     31     typedef Arg2   second_argument_type;
     32     typedef Result result_type;
     33 };
     34 
     35 template <class T>
     36 class reference_wrapper
     37     : public unary_function<T1, R> // if wrapping a unary functor
     38     : public binary_function<T1, T2, R> // if wraping a binary functor
     39 {
     40 public:
     41     // types
     42     typedef T type;
     43     typedef see below result_type; // Not always defined
     44 
     45     // construct/copy/destroy
     46     reference_wrapper(T&) noexcept;
     47     reference_wrapper(T&&) = delete; // do not bind to temps
     48     reference_wrapper(const reference_wrapper<T>& x) noexcept;
     49 
     50     // assignment
     51     reference_wrapper& operator=(const reference_wrapper<T>& x) noexcept;
     52 
     53     // access
     54     operator T& () const noexcept;
     55     T& get() const noexcept;
     56 
     57     // invoke
     58     template <class... ArgTypes>
     59       typename result_of<T&(ArgTypes&&...)>::type
     60           operator() (ArgTypes&&...) const;
     61 };
     62 
     63 template <class T> reference_wrapper<T> ref(T& t) noexcept;
     64 template <class T> void ref(const T&& t) = delete;
     65 template <class T> reference_wrapper<T> ref(reference_wrapper<T>t) noexcept;
     66 
     67 template <class T> reference_wrapper<const T> cref(const T& t) noexcept;
     68 template <class T> void cref(const T&& t) = delete;
     69 template <class T> reference_wrapper<const T> cref(reference_wrapper<T> t) noexcept;
     70 
     71 template <class T> struct unwrap_reference;                                       // since C++20
     72 template <class T> struct unwrap_ref_decay : unwrap_reference<decay_t<T>> { };    // since C++20
     73 template <class T> using unwrap_reference_t = typename unwrap_reference<T>::type; // since C++20
     74 template <class T> using unwrap_ref_decay_t = typename unwrap_ref_decay<T>::type; // since C++20
     75 
     76 template <class T> // <class T=void> in C++14
     77 struct plus : binary_function<T, T, T>
     78 {
     79     T operator()(const T& x, const T& y) const;
     80 };
     81 
     82 template <class T> // <class T=void> in C++14
     83 struct minus : binary_function<T, T, T>
     84 {
     85     T operator()(const T& x, const T& y) const;
     86 };
     87 
     88 template <class T> // <class T=void> in C++14
     89 struct multiplies : binary_function<T, T, T>
     90 {
     91     T operator()(const T& x, const T& y) const;
     92 };
     93 
     94 template <class T> // <class T=void> in C++14
     95 struct divides : binary_function<T, T, T>
     96 {
     97     T operator()(const T& x, const T& y) const;
     98 };
     99 
    100 template <class T> // <class T=void> in C++14
    101 struct modulus : binary_function<T, T, T>
    102 {
    103     T operator()(const T& x, const T& y) const;
    104 };
    105 
    106 template <class T> // <class T=void> in C++14
    107 struct negate : unary_function<T, T>
    108 {
    109     T operator()(const T& x) const;
    110 };
    111 
    112 template <class T> // <class T=void> in C++14
    113 struct equal_to : binary_function<T, T, bool>
    114 {
    115     bool operator()(const T& x, const T& y) const;
    116 };
    117 
    118 template <class T> // <class T=void> in C++14
    119 struct not_equal_to : binary_function<T, T, bool>
    120 {
    121     bool operator()(const T& x, const T& y) const;
    122 };
    123 
    124 template <class T> // <class T=void> in C++14
    125 struct greater : binary_function<T, T, bool>
    126 {
    127     bool operator()(const T& x, const T& y) const;
    128 };
    129 
    130 template <class T> // <class T=void> in C++14
    131 struct less : binary_function<T, T, bool>
    132 {
    133     bool operator()(const T& x, const T& y) const;
    134 };
    135 
    136 template <class T> // <class T=void> in C++14
    137 struct greater_equal : binary_function<T, T, bool>
    138 {
    139     bool operator()(const T& x, const T& y) const;
    140 };
    141 
    142 template <class T> // <class T=void> in C++14
    143 struct less_equal : binary_function<T, T, bool>
    144 {
    145     bool operator()(const T& x, const T& y) const;
    146 };
    147 
    148 template <class T> // <class T=void> in C++14
    149 struct logical_and : binary_function<T, T, bool>
    150 {
    151     bool operator()(const T& x, const T& y) const;
    152 };
    153 
    154 template <class T> // <class T=void> in C++14
    155 struct logical_or : binary_function<T, T, bool>
    156 {
    157     bool operator()(const T& x, const T& y) const;
    158 };
    159 
    160 template <class T> // <class T=void> in C++14
    161 struct logical_not : unary_function<T, bool>
    162 {
    163     bool operator()(const T& x) const;
    164 };
    165 
    166 template <class T> // <class T=void> in C++14
    167 struct bit_and : unary_function<T, bool>
    168 {
    169     bool operator()(const T& x, const T& y) const;
    170 };
    171 
    172 template <class T> // <class T=void> in C++14
    173 struct bit_or : unary_function<T, bool>
    174 {
    175     bool operator()(const T& x, const T& y) const;
    176 };
    177 
    178 template <class T> // <class T=void> in C++14
    179 struct bit_xor : unary_function<T, bool>
    180 {
    181     bool operator()(const T& x, const T& y) const;
    182 };
    183 
    184 template <class T=void> // C++14
    185 struct bit_xor : unary_function<T, bool>
    186 {
    187     bool operator()(const T& x) const;
    188 };
    189 
    190 template <class Predicate>
    191 class unary_negate // deprecated in C++17
    192     : public unary_function<typename Predicate::argument_type, bool>
    193 {
    194 public:
    195     explicit unary_negate(const Predicate& pred);
    196     bool operator()(const typename Predicate::argument_type& x) const;
    197 };
    198 
    199 template <class Predicate> // deprecated in C++17
    200 unary_negate<Predicate> not1(const Predicate& pred);
    201 
    202 template <class Predicate>
    203 class binary_negate // deprecated in C++17
    204     : public binary_function<typename Predicate::first_argument_type,
    205                              typename Predicate::second_argument_type,
    206                              bool>
    207 {
    208 public:
    209     explicit binary_negate(const Predicate& pred);
    210     bool operator()(const typename Predicate::first_argument_type& x,
    211                     const typename Predicate::second_argument_type& y) const;
    212 };
    213 
    214 template <class Predicate> // deprecated in C++17
    215 binary_negate<Predicate> not2(const Predicate& pred);
    216 
    217 template <class F> unspecified not_fn(F&& f); // C++17
    218 
    219 template<class T> struct is_bind_expression;
    220 template<class T> struct is_placeholder;
    221 
    222     // See C++14 20.9.9, Function object binders
    223 template <class T> inline constexpr bool is_bind_expression_v
    224   = is_bind_expression<T>::value; // C++17
    225 template <class T> inline constexpr int is_placeholder_v
    226   = is_placeholder<T>::value; // C++17
    227 
    228 
    229 template<class Fn, class... BoundArgs>
    230   unspecified bind(Fn&&, BoundArgs&&...);
    231 template<class R, class Fn, class... BoundArgs>
    232   unspecified bind(Fn&&, BoundArgs&&...);
    233 
    234 namespace placeholders {
    235   // M is the implementation-defined number of placeholders
    236   extern unspecified _1;
    237   extern unspecified _2;
    238   .
    239   .
    240   .
    241   extern unspecified _Mp;
    242 }
    243 
    244 template <class Operation>
    245 class binder1st     // deprecated in C++11, removed in C++17
    246     : public unary_function<typename Operation::second_argument_type,
    247                             typename Operation::result_type>
    248 {
    249 protected:
    250     Operation                               op;
    251     typename Operation::first_argument_type value;
    252 public:
    253     binder1st(const Operation& x, const typename Operation::first_argument_type y);
    254     typename Operation::result_type operator()(      typename Operation::second_argument_type& x) const;
    255     typename Operation::result_type operator()(const typename Operation::second_argument_type& x) const;
    256 };
    257 
    258 template <class Operation, class T>
    259 binder1st<Operation> bind1st(const Operation& op, const T& x);  // deprecated in C++11, removed in C++17
    260 
    261 template <class Operation>
    262 class binder2nd     // deprecated in C++11, removed in C++17
    263     : public unary_function<typename Operation::first_argument_type,
    264                             typename Operation::result_type>
    265 {
    266 protected:
    267     Operation                                op;
    268     typename Operation::second_argument_type value;
    269 public:
    270     binder2nd(const Operation& x, const typename Operation::second_argument_type y);
    271     typename Operation::result_type operator()(      typename Operation::first_argument_type& x) const;
    272     typename Operation::result_type operator()(const typename Operation::first_argument_type& x) const;
    273 };
    274 
    275 template <class Operation, class T>
    276 binder2nd<Operation> bind2nd(const Operation& op, const T& x);  // deprecated in C++11, removed in C++17
    277 
    278 template <class Arg, class Result>      // deprecated in C++11, removed in C++17
    279 class pointer_to_unary_function : public unary_function<Arg, Result>
    280 {
    281 public:
    282     explicit pointer_to_unary_function(Result (*f)(Arg));
    283     Result operator()(Arg x) const;
    284 };
    285 
    286 template <class Arg, class Result>
    287 pointer_to_unary_function<Arg,Result> ptr_fun(Result (*f)(Arg));      // deprecated in C++11, removed in C++17
    288 
    289 template <class Arg1, class Arg2, class Result>      // deprecated in C++11, removed in C++17
    290 class pointer_to_binary_function : public binary_function<Arg1, Arg2, Result>
    291 {
    292 public:
    293     explicit pointer_to_binary_function(Result (*f)(Arg1, Arg2));
    294     Result operator()(Arg1 x, Arg2 y) const;
    295 };
    296 
    297 template <class Arg1, class Arg2, class Result>
    298 pointer_to_binary_function<Arg1,Arg2,Result> ptr_fun(Result (*f)(Arg1,Arg2));      // deprecated in C++11, removed in C++17
    299 
    300 template<class S, class T>      // deprecated in C++11, removed in C++17
    301 class mem_fun_t : public unary_function<T*, S>
    302 {
    303 public:
    304     explicit mem_fun_t(S (T::*p)());
    305     S operator()(T* p) const;
    306 };
    307 
    308 template<class S, class T, class A>
    309 class mem_fun1_t : public binary_function<T*, A, S>      // deprecated in C++11, removed in C++17
    310 {
    311 public:
    312     explicit mem_fun1_t(S (T::*p)(A));
    313     S operator()(T* p, A x) const;
    314 };
    315 
    316 template<class S, class T>          mem_fun_t<S,T>    mem_fun(S (T::*f)());      // deprecated in C++11, removed in C++17
    317 template<class S, class T, class A> mem_fun1_t<S,T,A> mem_fun(S (T::*f)(A));     // deprecated in C++11, removed in C++17
    318 
    319 template<class S, class T>
    320 class mem_fun_ref_t : public unary_function<T, S>      // deprecated in C++11, removed in C++17
    321 {
    322 public:
    323     explicit mem_fun_ref_t(S (T::*p)());
    324     S operator()(T& p) const;
    325 };
    326 
    327 template<class S, class T, class A>
    328 class mem_fun1_ref_t : public binary_function<T, A, S>      // deprecated in C++11, removed in C++17
    329 {
    330 public:
    331     explicit mem_fun1_ref_t(S (T::*p)(A));
    332     S operator()(T& p, A x) const;
    333 };
    334 
    335 template<class S, class T>          mem_fun_ref_t<S,T>    mem_fun_ref(S (T::*f)());      // deprecated in C++11, removed in C++17
    336 template<class S, class T, class A> mem_fun1_ref_t<S,T,A> mem_fun_ref(S (T::*f)(A));     // deprecated in C++11, removed in C++17
    337 
    338 template <class S, class T>
    339 class const_mem_fun_t : public unary_function<const T*, S>      // deprecated in C++11, removed in C++17
    340 {
    341 public:
    342     explicit const_mem_fun_t(S (T::*p)() const);
    343     S operator()(const T* p) const;
    344 };
    345 
    346 template <class S, class T, class A>
    347 class const_mem_fun1_t : public binary_function<const T*, A, S>      // deprecated in C++11, removed in C++17
    348 {
    349 public:
    350     explicit const_mem_fun1_t(S (T::*p)(A) const);
    351     S operator()(const T* p, A x) const;
    352 };
    353 
    354 template <class S, class T>          const_mem_fun_t<S,T>    mem_fun(S (T::*f)() const);      // deprecated in C++11, removed in C++17
    355 template <class S, class T, class A> const_mem_fun1_t<S,T,A> mem_fun(S (T::*f)(A) const);     // deprecated in C++11, removed in C++17
    356 
    357 template <class S, class T>
    358 class const_mem_fun_ref_t : public unary_function<T, S>      // deprecated in C++11, removed in C++17
    359 {
    360 public:
    361     explicit const_mem_fun_ref_t(S (T::*p)() const);
    362     S operator()(const T& p) const;
    363 };
    364 
    365 template <class S, class T, class A>
    366 class const_mem_fun1_ref_t : public binary_function<T, A, S>      // deprecated in C++11, removed in C++17
    367 {
    368 public:
    369     explicit const_mem_fun1_ref_t(S (T::*p)(A) const);
    370     S operator()(const T& p, A x) const;
    371 };
    372 
    373 template <class S, class T>          const_mem_fun_ref_t<S,T>    mem_fun_ref(S (T::*f)() const);   // deprecated in C++11, removed in C++17
    374 template <class S, class T, class A> const_mem_fun1_ref_t<S,T,A> mem_fun_ref(S (T::*f)(A) const);  // deprecated in C++11, removed in C++17
    375 
    376 template<class R, class T> unspecified mem_fn(R T::*);
    377 
    378 class bad_function_call
    379     : public exception
    380 {
    381 };
    382 
    383 template<class> class function; // undefined
    384 
    385 template<class R, class... ArgTypes>
    386 class function<R(ArgTypes...)>
    387   : public unary_function<T1, R>      // iff sizeof...(ArgTypes) == 1 and
    388                                       // ArgTypes contains T1
    389   : public binary_function<T1, T2, R> // iff sizeof...(ArgTypes) == 2 and
    390                                       // ArgTypes contains T1 and T2
    391 {
    392 public:
    393     typedef R result_type;
    394 
    395     // construct/copy/destroy:
    396     function() noexcept;
    397     function(nullptr_t) noexcept;
    398     function(const function&);
    399     function(function&&) noexcept;
    400     template<class F>
    401       function(F);
    402     template<Allocator Alloc>
    403       function(allocator_arg_t, const Alloc&) noexcept;            // removed in C++17
    404     template<Allocator Alloc>
    405       function(allocator_arg_t, const Alloc&, nullptr_t) noexcept; // removed in C++17
    406     template<Allocator Alloc>
    407       function(allocator_arg_t, const Alloc&, const function&);    // removed in C++17
    408     template<Allocator Alloc>
    409       function(allocator_arg_t, const Alloc&, function&&);         // removed in C++17
    410     template<class F, Allocator Alloc>
    411       function(allocator_arg_t, const Alloc&, F);                  // removed in C++17
    412 
    413     function& operator=(const function&);
    414     function& operator=(function&&) noexcept;
    415     function& operator=(nullptr_t) noexcept;
    416     template<class F>
    417       function& operator=(F&&);
    418     template<class F>
    419       function& operator=(reference_wrapper<F>) noexcept;
    420 
    421     ~function();
    422 
    423     // function modifiers:
    424     void swap(function&) noexcept;
    425     template<class F, class Alloc>
    426       void assign(F&&, const Alloc&);                 // Removed in C++17
    427 
    428     // function capacity:
    429     explicit operator bool() const noexcept;
    430 
    431     // function invocation:
    432     R operator()(ArgTypes...) const;
    433 
    434     // function target access:
    435     const std::type_info& target_type() const noexcept;
    436     template <typename T>       T* target() noexcept;
    437     template <typename T> const T* target() const noexcept;
    438 };
    439 
    440 // Null pointer comparisons:
    441 template <class R, class ... ArgTypes>
    442   bool operator==(const function<R(ArgTypes...)>&, nullptr_t) noexcept;
    443 
    444 template <class R, class ... ArgTypes>
    445   bool operator==(nullptr_t, const function<R(ArgTypes...)>&) noexcept;
    446 
    447 template <class R, class ... ArgTypes>
    448   bool operator!=(const function<R(ArgTypes...)>&, nullptr_t) noexcept;
    449 
    450 template <class  R, class ... ArgTypes>
    451   bool operator!=(nullptr_t, const function<R(ArgTypes...)>&) noexcept;
    452 
    453 // specialized algorithms:
    454 template <class  R, class ... ArgTypes>
    455   void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&) noexcept;
    456 
    457 template <class T> struct hash;
    458 
    459 template <> struct hash<bool>;
    460 template <> struct hash<char>;
    461 template <> struct hash<signed char>;
    462 template <> struct hash<unsigned char>;
    463 template <> struct hash<char16_t>;
    464 template <> struct hash<char32_t>;
    465 template <> struct hash<wchar_t>;
    466 template <> struct hash<short>;
    467 template <> struct hash<unsigned short>;
    468 template <> struct hash<int>;
    469 template <> struct hash<unsigned int>;
    470 template <> struct hash<long>;
    471 template <> struct hash<long long>;
    472 template <> struct hash<unsigned long>;
    473 template <> struct hash<unsigned long long>;
    474 
    475 template <> struct hash<float>;
    476 template <> struct hash<double>;
    477 template <> struct hash<long double>;
    478 
    479 template<class T> struct hash<T*>;
    480 template <> struct hash<nullptr_t>;  // C++17
    481 
    482 }  // std
    483 
    484 POLICY:  For non-variadic implementations, the number of arguments is limited
    485          to 3.  It is hoped that the need for non-variadic implementations
    486          will be minimal.
    487 
    488 */
    489 
    490 #include <__config>
    491 #include <type_traits>
    492 #include <typeinfo>
    493 #include <exception>
    494 #include <memory>
    495 #include <tuple>
    496 #include <utility>
    497 #include <version>
    498 
    499 #include <__functional_base>
    500 
    501 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
    502 #pragma GCC system_header
    503 #endif
    504 
    505 _LIBCPP_BEGIN_NAMESPACE_STD
    506 
    507 #if _LIBCPP_STD_VER > 11
    508 template <class _Tp = void>
    509 #else
    510 template <class _Tp>
    511 #endif
    512 struct _LIBCPP_TEMPLATE_VIS plus : binary_function<_Tp, _Tp, _Tp>
    513 {
    514     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    515     _Tp operator()(const _Tp& __x, const _Tp& __y) const
    516         {return __x + __y;}
    517 };
    518 
    519 #if _LIBCPP_STD_VER > 11
    520 template <>
    521 struct _LIBCPP_TEMPLATE_VIS plus<void>
    522 {
    523     template <class _T1, class _T2>
    524     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    525     auto operator()(_T1&& __t, _T2&& __u) const
    526     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u)))
    527     -> decltype        (_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u))
    528         { return        _VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u); }
    529     typedef void is_transparent;
    530 };
    531 #endif
    532 
    533 
    534 #if _LIBCPP_STD_VER > 11
    535 template <class _Tp = void>
    536 #else
    537 template <class _Tp>
    538 #endif
    539 struct _LIBCPP_TEMPLATE_VIS minus : binary_function<_Tp, _Tp, _Tp>
    540 {
    541     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    542     _Tp operator()(const _Tp& __x, const _Tp& __y) const
    543         {return __x - __y;}
    544 };
    545 
    546 #if _LIBCPP_STD_VER > 11
    547 template <>
    548 struct _LIBCPP_TEMPLATE_VIS minus<void>
    549 {
    550     template <class _T1, class _T2>
    551     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    552     auto operator()(_T1&& __t, _T2&& __u) const
    553     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u)))
    554     -> decltype        (_VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u))
    555         { return        _VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u); }
    556     typedef void is_transparent;
    557 };
    558 #endif
    559 
    560 
    561 #if _LIBCPP_STD_VER > 11
    562 template <class _Tp = void>
    563 #else
    564 template <class _Tp>
    565 #endif
    566 struct _LIBCPP_TEMPLATE_VIS multiplies : binary_function<_Tp, _Tp, _Tp>
    567 {
    568     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    569     _Tp operator()(const _Tp& __x, const _Tp& __y) const
    570         {return __x * __y;}
    571 };
    572 
    573 #if _LIBCPP_STD_VER > 11
    574 template <>
    575 struct _LIBCPP_TEMPLATE_VIS multiplies<void>
    576 {
    577     template <class _T1, class _T2>
    578     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    579     auto operator()(_T1&& __t, _T2&& __u) const
    580     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u)))
    581     -> decltype        (_VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u))
    582         { return        _VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u); }
    583     typedef void is_transparent;
    584 };
    585 #endif
    586 
    587 
    588 #if _LIBCPP_STD_VER > 11
    589 template <class _Tp = void>
    590 #else
    591 template <class _Tp>
    592 #endif
    593 struct _LIBCPP_TEMPLATE_VIS divides : binary_function<_Tp, _Tp, _Tp>
    594 {
    595     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    596     _Tp operator()(const _Tp& __x, const _Tp& __y) const
    597         {return __x / __y;}
    598 };
    599 
    600 #if _LIBCPP_STD_VER > 11
    601 template <>
    602 struct _LIBCPP_TEMPLATE_VIS divides<void>
    603 {
    604     template <class _T1, class _T2>
    605     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    606     auto operator()(_T1&& __t, _T2&& __u) const
    607     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u)))
    608     -> decltype        (_VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u))
    609         { return        _VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u); }
    610     typedef void is_transparent;
    611 };
    612 #endif
    613 
    614 
    615 #if _LIBCPP_STD_VER > 11
    616 template <class _Tp = void>
    617 #else
    618 template <class _Tp>
    619 #endif
    620 struct _LIBCPP_TEMPLATE_VIS modulus : binary_function<_Tp, _Tp, _Tp>
    621 {
    622     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    623     _Tp operator()(const _Tp& __x, const _Tp& __y) const
    624         {return __x % __y;}
    625 };
    626 
    627 #if _LIBCPP_STD_VER > 11
    628 template <>
    629 struct _LIBCPP_TEMPLATE_VIS modulus<void>
    630 {
    631     template <class _T1, class _T2>
    632     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    633     auto operator()(_T1&& __t, _T2&& __u) const
    634     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u)))
    635     -> decltype        (_VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u))
    636         { return        _VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u); }
    637     typedef void is_transparent;
    638 };
    639 #endif
    640 
    641 
    642 #if _LIBCPP_STD_VER > 11
    643 template <class _Tp = void>
    644 #else
    645 template <class _Tp>
    646 #endif
    647 struct _LIBCPP_TEMPLATE_VIS negate : unary_function<_Tp, _Tp>
    648 {
    649     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    650     _Tp operator()(const _Tp& __x) const
    651         {return -__x;}
    652 };
    653 
    654 #if _LIBCPP_STD_VER > 11
    655 template <>
    656 struct _LIBCPP_TEMPLATE_VIS negate<void>
    657 {
    658     template <class _Tp>
    659     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    660     auto operator()(_Tp&& __x) const
    661     _NOEXCEPT_(noexcept(- _VSTD::forward<_Tp>(__x)))
    662     -> decltype        (- _VSTD::forward<_Tp>(__x))
    663         { return        - _VSTD::forward<_Tp>(__x); }
    664     typedef void is_transparent;
    665 };
    666 #endif
    667 
    668 
    669 #if _LIBCPP_STD_VER > 11
    670 template <class _Tp = void>
    671 #else
    672 template <class _Tp>
    673 #endif
    674 struct _LIBCPP_TEMPLATE_VIS equal_to : binary_function<_Tp, _Tp, bool>
    675 {
    676     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    677     bool operator()(const _Tp& __x, const _Tp& __y) const
    678         {return __x == __y;}
    679 };
    680 
    681 #if _LIBCPP_STD_VER > 11
    682 template <>
    683 struct _LIBCPP_TEMPLATE_VIS equal_to<void>
    684 {
    685     template <class _T1, class _T2>
    686     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    687     auto operator()(_T1&& __t, _T2&& __u) const
    688     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u)))
    689     -> decltype        (_VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u))
    690         { return        _VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u); }
    691     typedef void is_transparent;
    692 };
    693 #endif
    694 
    695 
    696 #if _LIBCPP_STD_VER > 11
    697 template <class _Tp = void>
    698 #else
    699 template <class _Tp>
    700 #endif
    701 struct _LIBCPP_TEMPLATE_VIS not_equal_to : binary_function<_Tp, _Tp, bool>
    702 {
    703     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    704     bool operator()(const _Tp& __x, const _Tp& __y) const
    705         {return __x != __y;}
    706 };
    707 
    708 #if _LIBCPP_STD_VER > 11
    709 template <>
    710 struct _LIBCPP_TEMPLATE_VIS not_equal_to<void>
    711 {
    712     template <class _T1, class _T2>
    713     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    714     auto operator()(_T1&& __t, _T2&& __u) const
    715     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u)))
    716     -> decltype        (_VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u))
    717         { return        _VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u); }
    718     typedef void is_transparent;
    719 };
    720 #endif
    721 
    722 
    723 #if _LIBCPP_STD_VER > 11
    724 template <class _Tp = void>
    725 #else
    726 template <class _Tp>
    727 #endif
    728 struct _LIBCPP_TEMPLATE_VIS greater : binary_function<_Tp, _Tp, bool>
    729 {
    730     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    731     bool operator()(const _Tp& __x, const _Tp& __y) const
    732         {return __x > __y;}
    733 };
    734 
    735 #if _LIBCPP_STD_VER > 11
    736 template <>
    737 struct _LIBCPP_TEMPLATE_VIS greater<void>
    738 {
    739     template <class _T1, class _T2>
    740     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    741     auto operator()(_T1&& __t, _T2&& __u) const
    742     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u)))
    743     -> decltype        (_VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u))
    744         { return        _VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u); }
    745     typedef void is_transparent;
    746 };
    747 #endif
    748 
    749 
    750 // less in <__functional_base>
    751 
    752 #if _LIBCPP_STD_VER > 11
    753 template <class _Tp = void>
    754 #else
    755 template <class _Tp>
    756 #endif
    757 struct _LIBCPP_TEMPLATE_VIS greater_equal : binary_function<_Tp, _Tp, bool>
    758 {
    759     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    760     bool operator()(const _Tp& __x, const _Tp& __y) const
    761         {return __x >= __y;}
    762 };
    763 
    764 #if _LIBCPP_STD_VER > 11
    765 template <>
    766 struct _LIBCPP_TEMPLATE_VIS greater_equal<void>
    767 {
    768     template <class _T1, class _T2>
    769     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    770     auto operator()(_T1&& __t, _T2&& __u) const
    771     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u)))
    772     -> decltype        (_VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u))
    773         { return        _VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u); }
    774     typedef void is_transparent;
    775 };
    776 #endif
    777 
    778 
    779 #if _LIBCPP_STD_VER > 11
    780 template <class _Tp = void>
    781 #else
    782 template <class _Tp>
    783 #endif
    784 struct _LIBCPP_TEMPLATE_VIS less_equal : binary_function<_Tp, _Tp, bool>
    785 {
    786     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    787     bool operator()(const _Tp& __x, const _Tp& __y) const
    788         {return __x <= __y;}
    789 };
    790 
    791 #if _LIBCPP_STD_VER > 11
    792 template <>
    793 struct _LIBCPP_TEMPLATE_VIS less_equal<void>
    794 {
    795     template <class _T1, class _T2>
    796     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    797     auto operator()(_T1&& __t, _T2&& __u) const
    798     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u)))
    799     -> decltype        (_VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u))
    800         { return        _VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u); }
    801     typedef void is_transparent;
    802 };
    803 #endif
    804 
    805 
    806 #if _LIBCPP_STD_VER > 11
    807 template <class _Tp = void>
    808 #else
    809 template <class _Tp>
    810 #endif
    811 struct _LIBCPP_TEMPLATE_VIS logical_and : binary_function<_Tp, _Tp, bool>
    812 {
    813     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    814     bool operator()(const _Tp& __x, const _Tp& __y) const
    815         {return __x && __y;}
    816 };
    817 
    818 #if _LIBCPP_STD_VER > 11
    819 template <>
    820 struct _LIBCPP_TEMPLATE_VIS logical_and<void>
    821 {
    822     template <class _T1, class _T2>
    823     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    824     auto operator()(_T1&& __t, _T2&& __u) const
    825     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u)))
    826     -> decltype        (_VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u))
    827         { return        _VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u); }
    828     typedef void is_transparent;
    829 };
    830 #endif
    831 
    832 
    833 #if _LIBCPP_STD_VER > 11
    834 template <class _Tp = void>
    835 #else
    836 template <class _Tp>
    837 #endif
    838 struct _LIBCPP_TEMPLATE_VIS logical_or : binary_function<_Tp, _Tp, bool>
    839 {
    840     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    841     bool operator()(const _Tp& __x, const _Tp& __y) const
    842         {return __x || __y;}
    843 };
    844 
    845 #if _LIBCPP_STD_VER > 11
    846 template <>
    847 struct _LIBCPP_TEMPLATE_VIS logical_or<void>
    848 {
    849     template <class _T1, class _T2>
    850     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    851     auto operator()(_T1&& __t, _T2&& __u) const
    852     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u)))
    853     -> decltype        (_VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u))
    854         { return        _VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u); }
    855     typedef void is_transparent;
    856 };
    857 #endif
    858 
    859 
    860 #if _LIBCPP_STD_VER > 11
    861 template <class _Tp = void>
    862 #else
    863 template <class _Tp>
    864 #endif
    865 struct _LIBCPP_TEMPLATE_VIS logical_not : unary_function<_Tp, bool>
    866 {
    867     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    868     bool operator()(const _Tp& __x) const
    869         {return !__x;}
    870 };
    871 
    872 #if _LIBCPP_STD_VER > 11
    873 template <>
    874 struct _LIBCPP_TEMPLATE_VIS logical_not<void>
    875 {
    876     template <class _Tp>
    877     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    878     auto operator()(_Tp&& __x) const
    879     _NOEXCEPT_(noexcept(!_VSTD::forward<_Tp>(__x)))
    880     -> decltype        (!_VSTD::forward<_Tp>(__x))
    881         { return        !_VSTD::forward<_Tp>(__x); }
    882     typedef void is_transparent;
    883 };
    884 #endif
    885 
    886 
    887 #if _LIBCPP_STD_VER > 11
    888 template <class _Tp = void>
    889 #else
    890 template <class _Tp>
    891 #endif
    892 struct _LIBCPP_TEMPLATE_VIS bit_and : binary_function<_Tp, _Tp, _Tp>
    893 {
    894     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    895     _Tp operator()(const _Tp& __x, const _Tp& __y) const
    896         {return __x & __y;}
    897 };
    898 
    899 #if _LIBCPP_STD_VER > 11
    900 template <>
    901 struct _LIBCPP_TEMPLATE_VIS bit_and<void>
    902 {
    903     template <class _T1, class _T2>
    904     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    905     auto operator()(_T1&& __t, _T2&& __u) const
    906     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u)))
    907     -> decltype        (_VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u))
    908         { return        _VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u); }
    909     typedef void is_transparent;
    910 };
    911 #endif
    912 
    913 
    914 #if _LIBCPP_STD_VER > 11
    915 template <class _Tp = void>
    916 #else
    917 template <class _Tp>
    918 #endif
    919 struct _LIBCPP_TEMPLATE_VIS bit_or : binary_function<_Tp, _Tp, _Tp>
    920 {
    921     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    922     _Tp operator()(const _Tp& __x, const _Tp& __y) const
    923         {return __x | __y;}
    924 };
    925 
    926 #if _LIBCPP_STD_VER > 11
    927 template <>
    928 struct _LIBCPP_TEMPLATE_VIS bit_or<void>
    929 {
    930     template <class _T1, class _T2>
    931     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    932     auto operator()(_T1&& __t, _T2&& __u) const
    933     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u)))
    934     -> decltype        (_VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u))
    935         { return        _VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u); }
    936     typedef void is_transparent;
    937 };
    938 #endif
    939 
    940 
    941 #if _LIBCPP_STD_VER > 11
    942 template <class _Tp = void>
    943 #else
    944 template <class _Tp>
    945 #endif
    946 struct _LIBCPP_TEMPLATE_VIS bit_xor : binary_function<_Tp, _Tp, _Tp>
    947 {
    948     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    949     _Tp operator()(const _Tp& __x, const _Tp& __y) const
    950         {return __x ^ __y;}
    951 };
    952 
    953 #if _LIBCPP_STD_VER > 11
    954 template <>
    955 struct _LIBCPP_TEMPLATE_VIS bit_xor<void>
    956 {
    957     template <class _T1, class _T2>
    958     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    959     auto operator()(_T1&& __t, _T2&& __u) const
    960     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u)))
    961     -> decltype        (_VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u))
    962         { return        _VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u); }
    963     typedef void is_transparent;
    964 };
    965 #endif
    966 
    967 
    968 #if _LIBCPP_STD_VER > 11
    969 template <class _Tp = void>
    970 struct _LIBCPP_TEMPLATE_VIS bit_not : unary_function<_Tp, _Tp>
    971 {
    972     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    973     _Tp operator()(const _Tp& __x) const
    974         {return ~__x;}
    975 };
    976 
    977 template <>
    978 struct _LIBCPP_TEMPLATE_VIS bit_not<void>
    979 {
    980     template <class _Tp>
    981     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    982     auto operator()(_Tp&& __x) const
    983     _NOEXCEPT_(noexcept(~_VSTD::forward<_Tp>(__x)))
    984     -> decltype        (~_VSTD::forward<_Tp>(__x))
    985         { return        ~_VSTD::forward<_Tp>(__x); }
    986     typedef void is_transparent;
    987 };
    988 #endif
    989 
    990 template <class _Predicate>
    991 class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX17 unary_negate
    992     : public unary_function<typename _Predicate::argument_type, bool>
    993 {
    994     _Predicate __pred_;
    995 public:
    996     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
    997     explicit unary_negate(const _Predicate& __pred)
    998         : __pred_(__pred) {}
    999     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
   1000     bool operator()(const typename _Predicate::argument_type& __x) const
   1001         {return !__pred_(__x);}
   1002 };
   1003 
   1004 template <class _Predicate>
   1005 _LIBCPP_DEPRECATED_IN_CXX17 inline _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
   1006 unary_negate<_Predicate>
   1007 not1(const _Predicate& __pred) {return unary_negate<_Predicate>(__pred);}
   1008 
   1009 template <class _Predicate>
   1010 class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX17 binary_negate
   1011     : public binary_function<typename _Predicate::first_argument_type,
   1012                              typename _Predicate::second_argument_type,
   1013                              bool>
   1014 {
   1015     _Predicate __pred_;
   1016 public:
   1017     _LIBCPP_INLINE_VISIBILITY explicit _LIBCPP_CONSTEXPR_AFTER_CXX11
   1018     binary_negate(const _Predicate& __pred) : __pred_(__pred) {}
   1019 
   1020     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
   1021     bool operator()(const typename _Predicate::first_argument_type& __x,
   1022                     const typename _Predicate::second_argument_type& __y) const
   1023         {return !__pred_(__x, __y);}
   1024 };
   1025 
   1026 template <class _Predicate>
   1027 _LIBCPP_DEPRECATED_IN_CXX17 inline _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
   1028 binary_negate<_Predicate>
   1029 not2(const _Predicate& __pred) {return binary_negate<_Predicate>(__pred);}
   1030 
   1031 #if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_BINDERS)
   1032 template <class __Operation>
   1033 class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 binder1st
   1034     : public unary_function<typename __Operation::second_argument_type,
   1035                             typename __Operation::result_type>
   1036 {
   1037 protected:
   1038     __Operation                               op;
   1039     typename __Operation::first_argument_type value;
   1040 public:
   1041     _LIBCPP_INLINE_VISIBILITY binder1st(const __Operation& __x,
   1042                                const typename __Operation::first_argument_type __y)
   1043         : op(__x), value(__y) {}
   1044     _LIBCPP_INLINE_VISIBILITY typename __Operation::result_type operator()
   1045         (typename __Operation::second_argument_type& __x) const
   1046             {return op(value, __x);}
   1047     _LIBCPP_INLINE_VISIBILITY typename __Operation::result_type operator()
   1048         (const typename __Operation::second_argument_type& __x) const
   1049             {return op(value, __x);}
   1050 };
   1051 
   1052 template <class __Operation, class _Tp>
   1053 _LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
   1054 binder1st<__Operation>
   1055 bind1st(const __Operation& __op, const _Tp& __x)
   1056     {return binder1st<__Operation>(__op, __x);}
   1057 
   1058 template <class __Operation>
   1059 class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 binder2nd
   1060     : public unary_function<typename __Operation::first_argument_type,
   1061                             typename __Operation::result_type>
   1062 {
   1063 protected:
   1064     __Operation                                op;
   1065     typename __Operation::second_argument_type value;
   1066 public:
   1067     _LIBCPP_INLINE_VISIBILITY
   1068     binder2nd(const __Operation& __x, const typename __Operation::second_argument_type __y)
   1069         : op(__x), value(__y) {}
   1070     _LIBCPP_INLINE_VISIBILITY typename __Operation::result_type operator()
   1071         (      typename __Operation::first_argument_type& __x) const
   1072             {return op(__x, value);}
   1073     _LIBCPP_INLINE_VISIBILITY typename __Operation::result_type operator()
   1074         (const typename __Operation::first_argument_type& __x) const
   1075             {return op(__x, value);}
   1076 };
   1077 
   1078 template <class __Operation, class _Tp>
   1079 _LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
   1080 binder2nd<__Operation>
   1081 bind2nd(const __Operation& __op, const _Tp& __x)
   1082     {return binder2nd<__Operation>(__op, __x);}
   1083 
   1084 template <class _Arg, class _Result>
   1085 class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 pointer_to_unary_function
   1086     : public unary_function<_Arg, _Result>
   1087 {
   1088     _Result (*__f_)(_Arg);
   1089 public:
   1090     _LIBCPP_INLINE_VISIBILITY explicit pointer_to_unary_function(_Result (*__f)(_Arg))
   1091         : __f_(__f) {}
   1092     _LIBCPP_INLINE_VISIBILITY _Result operator()(_Arg __x) const
   1093         {return __f_(__x);}
   1094 };
   1095 
   1096 template <class _Arg, class _Result>
   1097 _LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
   1098 pointer_to_unary_function<_Arg,_Result>
   1099 ptr_fun(_Result (*__f)(_Arg))
   1100     {return pointer_to_unary_function<_Arg,_Result>(__f);}
   1101 
   1102 template <class _Arg1, class _Arg2, class _Result>
   1103 class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 pointer_to_binary_function
   1104     : public binary_function<_Arg1, _Arg2, _Result>
   1105 {
   1106     _Result (*__f_)(_Arg1, _Arg2);
   1107 public:
   1108     _LIBCPP_INLINE_VISIBILITY explicit pointer_to_binary_function(_Result (*__f)(_Arg1, _Arg2))
   1109         : __f_(__f) {}
   1110     _LIBCPP_INLINE_VISIBILITY _Result operator()(_Arg1 __x, _Arg2 __y) const
   1111         {return __f_(__x, __y);}
   1112 };
   1113 
   1114 template <class _Arg1, class _Arg2, class _Result>
   1115 _LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
   1116 pointer_to_binary_function<_Arg1,_Arg2,_Result>
   1117 ptr_fun(_Result (*__f)(_Arg1,_Arg2))
   1118     {return pointer_to_binary_function<_Arg1,_Arg2,_Result>(__f);}
   1119 
   1120 template<class _Sp, class _Tp>
   1121 class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 mem_fun_t
   1122     : public unary_function<_Tp*, _Sp>
   1123 {
   1124     _Sp (_Tp::*__p_)();
   1125 public:
   1126     _LIBCPP_INLINE_VISIBILITY explicit mem_fun_t(_Sp (_Tp::*__p)())
   1127         : __p_(__p) {}
   1128     _LIBCPP_INLINE_VISIBILITY _Sp operator()(_Tp* __p) const
   1129         {return (__p->*__p_)();}
   1130 };
   1131 
   1132 template<class _Sp, class _Tp, class _Ap>
   1133 class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 mem_fun1_t
   1134     : public binary_function<_Tp*, _Ap, _Sp>
   1135 {
   1136     _Sp (_Tp::*__p_)(_Ap);
   1137 public:
   1138     _LIBCPP_INLINE_VISIBILITY explicit mem_fun1_t(_Sp (_Tp::*__p)(_Ap))
   1139         : __p_(__p) {}
   1140     _LIBCPP_INLINE_VISIBILITY _Sp operator()(_Tp* __p, _Ap __x) const
   1141         {return (__p->*__p_)(__x);}
   1142 };
   1143 
   1144 template<class _Sp, class _Tp>
   1145 _LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
   1146 mem_fun_t<_Sp,_Tp>
   1147 mem_fun(_Sp (_Tp::*__f)())
   1148     {return mem_fun_t<_Sp,_Tp>(__f);}
   1149 
   1150 template<class _Sp, class _Tp, class _Ap>
   1151 _LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
   1152 mem_fun1_t<_Sp,_Tp,_Ap>
   1153 mem_fun(_Sp (_Tp::*__f)(_Ap))
   1154     {return mem_fun1_t<_Sp,_Tp,_Ap>(__f);}
   1155 
   1156 template<class _Sp, class _Tp>
   1157 class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 mem_fun_ref_t
   1158     : public unary_function<_Tp, _Sp>
   1159 {
   1160     _Sp (_Tp::*__p_)();
   1161 public:
   1162     _LIBCPP_INLINE_VISIBILITY explicit mem_fun_ref_t(_Sp (_Tp::*__p)())
   1163         : __p_(__p) {}
   1164     _LIBCPP_INLINE_VISIBILITY _Sp operator()(_Tp& __p) const
   1165         {return (__p.*__p_)();}
   1166 };
   1167 
   1168 template<class _Sp, class _Tp, class _Ap>
   1169 class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 mem_fun1_ref_t
   1170     : public binary_function<_Tp, _Ap, _Sp>
   1171 {
   1172     _Sp (_Tp::*__p_)(_Ap);
   1173 public:
   1174     _LIBCPP_INLINE_VISIBILITY explicit mem_fun1_ref_t(_Sp (_Tp::*__p)(_Ap))
   1175         : __p_(__p) {}
   1176     _LIBCPP_INLINE_VISIBILITY _Sp operator()(_Tp& __p, _Ap __x) const
   1177         {return (__p.*__p_)(__x);}
   1178 };
   1179 
   1180 template<class _Sp, class _Tp>
   1181 _LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
   1182 mem_fun_ref_t<_Sp,_Tp>
   1183 mem_fun_ref(_Sp (_Tp::*__f)())
   1184     {return mem_fun_ref_t<_Sp,_Tp>(__f);}
   1185 
   1186 template<class _Sp, class _Tp, class _Ap>
   1187 _LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
   1188 mem_fun1_ref_t<_Sp,_Tp,_Ap>
   1189 mem_fun_ref(_Sp (_Tp::*__f)(_Ap))
   1190     {return mem_fun1_ref_t<_Sp,_Tp,_Ap>(__f);}
   1191 
   1192 template <class _Sp, class _Tp>
   1193 class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 const_mem_fun_t
   1194     : public unary_function<const _Tp*, _Sp>
   1195 {
   1196     _Sp (_Tp::*__p_)() const;
   1197 public:
   1198     _LIBCPP_INLINE_VISIBILITY explicit const_mem_fun_t(_Sp (_Tp::*__p)() const)
   1199         : __p_(__p) {}
   1200     _LIBCPP_INLINE_VISIBILITY _Sp operator()(const _Tp* __p) const
   1201         {return (__p->*__p_)();}
   1202 };
   1203 
   1204 template <class _Sp, class _Tp, class _Ap>
   1205 class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 const_mem_fun1_t
   1206     : public binary_function<const _Tp*, _Ap, _Sp>
   1207 {
   1208     _Sp (_Tp::*__p_)(_Ap) const;
   1209 public:
   1210     _LIBCPP_INLINE_VISIBILITY explicit const_mem_fun1_t(_Sp (_Tp::*__p)(_Ap) const)
   1211         : __p_(__p) {}
   1212     _LIBCPP_INLINE_VISIBILITY _Sp operator()(const _Tp* __p, _Ap __x) const
   1213         {return (__p->*__p_)(__x);}
   1214 };
   1215 
   1216 template <class _Sp, class _Tp>
   1217 _LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
   1218 const_mem_fun_t<_Sp,_Tp>
   1219 mem_fun(_Sp (_Tp::*__f)() const)
   1220     {return const_mem_fun_t<_Sp,_Tp>(__f);}
   1221 
   1222 template <class _Sp, class _Tp, class _Ap>
   1223 _LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
   1224 const_mem_fun1_t<_Sp,_Tp,_Ap>
   1225 mem_fun(_Sp (_Tp::*__f)(_Ap) const)
   1226     {return const_mem_fun1_t<_Sp,_Tp,_Ap>(__f);}
   1227 
   1228 template <class _Sp, class _Tp>
   1229 class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 const_mem_fun_ref_t
   1230     : public unary_function<_Tp, _Sp>
   1231 {
   1232     _Sp (_Tp::*__p_)() const;
   1233 public:
   1234     _LIBCPP_INLINE_VISIBILITY explicit const_mem_fun_ref_t(_Sp (_Tp::*__p)() const)
   1235         : __p_(__p) {}
   1236     _LIBCPP_INLINE_VISIBILITY _Sp operator()(const _Tp& __p) const
   1237         {return (__p.*__p_)();}
   1238 };
   1239 
   1240 template <class _Sp, class _Tp, class _Ap>
   1241 class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 const_mem_fun1_ref_t
   1242     : public binary_function<_Tp, _Ap, _Sp>
   1243 {
   1244     _Sp (_Tp::*__p_)(_Ap) const;
   1245 public:
   1246     _LIBCPP_INLINE_VISIBILITY explicit const_mem_fun1_ref_t(_Sp (_Tp::*__p)(_Ap) const)
   1247         : __p_(__p) {}
   1248     _LIBCPP_INLINE_VISIBILITY _Sp operator()(const _Tp& __p, _Ap __x) const
   1249         {return (__p.*__p_)(__x);}
   1250 };
   1251 
   1252 template <class _Sp, class _Tp>
   1253 _LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
   1254 const_mem_fun_ref_t<_Sp,_Tp>
   1255 mem_fun_ref(_Sp (_Tp::*__f)() const)
   1256     {return const_mem_fun_ref_t<_Sp,_Tp>(__f);}
   1257 
   1258 template <class _Sp, class _Tp, class _Ap>
   1259 _LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
   1260 const_mem_fun1_ref_t<_Sp,_Tp,_Ap>
   1261 mem_fun_ref(_Sp (_Tp::*__f)(_Ap) const)
   1262     {return const_mem_fun1_ref_t<_Sp,_Tp,_Ap>(__f);}
   1263 #endif
   1264 
   1265 ////////////////////////////////////////////////////////////////////////////////
   1266 //                                MEMFUN
   1267 //==============================================================================
   1268 
   1269 template <class _Tp>
   1270 class __mem_fn
   1271     : public __weak_result_type<_Tp>
   1272 {
   1273 public:
   1274     // types
   1275     typedef _Tp type;
   1276 private:
   1277     type __f_;
   1278 
   1279 public:
   1280     _LIBCPP_INLINE_VISIBILITY __mem_fn(type __f) _NOEXCEPT : __f_(__f) {}
   1281 
   1282 #ifndef _LIBCPP_CXX03_LANG
   1283     // invoke
   1284     template <class... _ArgTypes>
   1285     _LIBCPP_INLINE_VISIBILITY
   1286     typename __invoke_return<type, _ArgTypes...>::type
   1287     operator() (_ArgTypes&&... __args) const {
   1288         return __invoke(__f_, _VSTD::forward<_ArgTypes>(__args)...);
   1289     }
   1290 #else
   1291 
   1292     template <class _A0>
   1293     _LIBCPP_INLINE_VISIBILITY
   1294     typename __invoke_return0<type, _A0>::type
   1295     operator() (_A0& __a0) const {
   1296         return __invoke(__f_, __a0);
   1297     }
   1298 
   1299     template <class _A0>
   1300     _LIBCPP_INLINE_VISIBILITY
   1301     typename __invoke_return0<type, _A0 const>::type
   1302     operator() (_A0 const& __a0) const {
   1303         return __invoke(__f_, __a0);
   1304     }
   1305 
   1306     template <class _A0, class _A1>
   1307     _LIBCPP_INLINE_VISIBILITY
   1308     typename __invoke_return1<type, _A0, _A1>::type
   1309     operator() (_A0& __a0, _A1& __a1) const {
   1310         return __invoke(__f_, __a0, __a1);
   1311     }
   1312 
   1313     template <class _A0, class _A1>
   1314     _LIBCPP_INLINE_VISIBILITY
   1315     typename __invoke_return1<type, _A0 const, _A1>::type
   1316     operator() (_A0 const& __a0, _A1& __a1) const {
   1317         return __invoke(__f_, __a0, __a1);
   1318     }
   1319 
   1320     template <class _A0, class _A1>
   1321     _LIBCPP_INLINE_VISIBILITY
   1322     typename __invoke_return1<type, _A0, _A1 const>::type
   1323     operator() (_A0& __a0, _A1 const& __a1) const {
   1324         return __invoke(__f_, __a0, __a1);
   1325     }
   1326 
   1327     template <class _A0, class _A1>
   1328     _LIBCPP_INLINE_VISIBILITY
   1329     typename __invoke_return1<type, _A0 const, _A1 const>::type
   1330     operator() (_A0 const& __a0, _A1 const& __a1) const {
   1331         return __invoke(__f_, __a0, __a1);
   1332     }
   1333 
   1334     template <class _A0, class _A1, class _A2>
   1335     _LIBCPP_INLINE_VISIBILITY
   1336     typename __invoke_return2<type, _A0, _A1, _A2>::type
   1337     operator() (_A0& __a0, _A1& __a1, _A2& __a2) const {
   1338         return __invoke(__f_, __a0, __a1, __a2);
   1339     }
   1340 
   1341     template <class _A0, class _A1, class _A2>
   1342     _LIBCPP_INLINE_VISIBILITY
   1343     typename __invoke_return2<type, _A0 const, _A1, _A2>::type
   1344     operator() (_A0 const& __a0, _A1& __a1, _A2& __a2) const {
   1345         return __invoke(__f_, __a0, __a1, __a2);
   1346     }
   1347 
   1348     template <class _A0, class _A1, class _A2>
   1349     _LIBCPP_INLINE_VISIBILITY
   1350     typename __invoke_return2<type, _A0, _A1 const, _A2>::type
   1351     operator() (_A0& __a0, _A1 const& __a1, _A2& __a2) const {
   1352         return __invoke(__f_, __a0, __a1, __a2);
   1353     }
   1354 
   1355     template <class _A0, class _A1, class _A2>
   1356     _LIBCPP_INLINE_VISIBILITY
   1357     typename __invoke_return2<type, _A0, _A1, _A2 const>::type
   1358     operator() (_A0& __a0, _A1& __a1, _A2 const& __a2) const {
   1359         return __invoke(__f_, __a0, __a1, __a2);
   1360     }
   1361 
   1362     template <class _A0, class _A1, class _A2>
   1363     _LIBCPP_INLINE_VISIBILITY
   1364     typename __invoke_return2<type, _A0 const, _A1 const, _A2>::type
   1365     operator() (_A0 const& __a0, _A1 const& __a1, _A2& __a2) const {
   1366         return __invoke(__f_, __a0, __a1, __a2);
   1367     }
   1368 
   1369     template <class _A0, class _A1, class _A2>
   1370     _LIBCPP_INLINE_VISIBILITY
   1371     typename __invoke_return2<type, _A0 const, _A1, _A2 const>::type
   1372     operator() (_A0 const& __a0, _A1& __a1, _A2 const& __a2) const {
   1373         return __invoke(__f_, __a0, __a1, __a2);
   1374     }
   1375 
   1376     template <class _A0, class _A1, class _A2>
   1377     _LIBCPP_INLINE_VISIBILITY
   1378     typename __invoke_return2<type, _A0, _A1 const, _A2 const>::type
   1379     operator() (_A0& __a0, _A1 const& __a1, _A2 const& __a2) const {
   1380         return __invoke(__f_, __a0, __a1, __a2);
   1381     }
   1382 
   1383     template <class _A0, class _A1, class _A2>
   1384     _LIBCPP_INLINE_VISIBILITY
   1385     typename __invoke_return2<type, _A0 const, _A1 const, _A2 const>::type
   1386     operator() (_A0 const& __a0, _A1 const& __a1, _A2 const& __a2) const {
   1387         return __invoke(__f_, __a0, __a1, __a2);
   1388     }
   1389 #endif
   1390 };
   1391 
   1392 template<class _Rp, class _Tp>
   1393 inline _LIBCPP_INLINE_VISIBILITY
   1394 __mem_fn<_Rp _Tp::*>
   1395 mem_fn(_Rp _Tp::* __pm) _NOEXCEPT
   1396 {
   1397     return __mem_fn<_Rp _Tp::*>(__pm);
   1398 }
   1399 
   1400 ////////////////////////////////////////////////////////////////////////////////
   1401 //                                FUNCTION
   1402 //==============================================================================
   1403 
   1404 // bad_function_call
   1405 
   1406 class _LIBCPP_EXCEPTION_ABI bad_function_call
   1407     : public exception
   1408 {
   1409 #ifdef _LIBCPP_ABI_BAD_FUNCTION_CALL_KEY_FUNCTION
   1410 public:
   1411     virtual ~bad_function_call() _NOEXCEPT;
   1412 
   1413     virtual const char* what() const _NOEXCEPT;
   1414 #endif
   1415 };
   1416 
   1417 _LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
   1418 void __throw_bad_function_call()
   1419 {
   1420 #ifndef _LIBCPP_NO_EXCEPTIONS
   1421     throw bad_function_call();
   1422 #else
   1423     _VSTD::abort();
   1424 #endif
   1425 }
   1426 
   1427 template<class _Fp> class _LIBCPP_TEMPLATE_VIS function; // undefined
   1428 
   1429 namespace __function
   1430 {
   1431 
   1432 template<class _Rp>
   1433 struct __maybe_derive_from_unary_function
   1434 {
   1435 };
   1436 
   1437 template<class _Rp, class _A1>
   1438 struct __maybe_derive_from_unary_function<_Rp(_A1)>
   1439     : public unary_function<_A1, _Rp>
   1440 {
   1441 };
   1442 
   1443 template<class _Rp>
   1444 struct __maybe_derive_from_binary_function
   1445 {
   1446 };
   1447 
   1448 template<class _Rp, class _A1, class _A2>
   1449 struct __maybe_derive_from_binary_function<_Rp(_A1, _A2)>
   1450     : public binary_function<_A1, _A2, _Rp>
   1451 {
   1452 };
   1453 
   1454 template <class _Fp>
   1455 _LIBCPP_INLINE_VISIBILITY
   1456 bool __not_null(_Fp const&) { return true; }
   1457 
   1458 template <class _Fp>
   1459 _LIBCPP_INLINE_VISIBILITY
   1460 bool __not_null(_Fp* __ptr) { return __ptr; }
   1461 
   1462 template <class _Ret, class _Class>
   1463 _LIBCPP_INLINE_VISIBILITY
   1464 bool __not_null(_Ret _Class::*__ptr) { return __ptr; }
   1465 
   1466 template <class _Fp>
   1467 _LIBCPP_INLINE_VISIBILITY
   1468 bool __not_null(function<_Fp> const& __f) { return !!__f; }
   1469 
   1470 } // namespace __function
   1471 
   1472 #ifndef _LIBCPP_CXX03_LANG
   1473 
   1474 namespace __function {
   1475 
   1476 // __alloc_func holds a functor and an allocator.
   1477 
   1478 template <class _Fp, class _Ap, class _FB> class __alloc_func;
   1479 
   1480 template <class _Fp, class _Ap, class _Rp, class... _ArgTypes>
   1481 class __alloc_func<_Fp, _Ap, _Rp(_ArgTypes...)>
   1482 {
   1483     __compressed_pair<_Fp, _Ap> __f_;
   1484 
   1485   public:
   1486     typedef _Fp _Target;
   1487     typedef _Ap _Alloc;
   1488 
   1489     _LIBCPP_INLINE_VISIBILITY
   1490     const _Target& __target() const { return __f_.first(); }
   1491 
   1492   // thank you M$ defining every possible identifier to some junk
   1493 #ifdef __allocator
   1494 #undef __allocator
   1495 #endif
   1496     _LIBCPP_INLINE_VISIBILITY
   1497     const _Alloc& __allocator() const { return __f_.second(); }
   1498 
   1499     _LIBCPP_INLINE_VISIBILITY
   1500     explicit __alloc_func(_Target&& __f)
   1501         : __f_(piecewise_construct, _VSTD::forward_as_tuple(_VSTD::move(__f)),
   1502                _VSTD::forward_as_tuple())
   1503     {
   1504     }
   1505 
   1506     _LIBCPP_INLINE_VISIBILITY
   1507     explicit __alloc_func(const _Target& __f, const _Alloc& __a)
   1508         : __f_(piecewise_construct, _VSTD::forward_as_tuple(__f),
   1509                _VSTD::forward_as_tuple(__a))
   1510     {
   1511     }
   1512 
   1513     _LIBCPP_INLINE_VISIBILITY
   1514     explicit __alloc_func(const _Target& __f, _Alloc&& __a)
   1515         : __f_(piecewise_construct, _VSTD::forward_as_tuple(__f),
   1516                _VSTD::forward_as_tuple(_VSTD::move(__a)))
   1517     {
   1518     }
   1519 
   1520     _LIBCPP_INLINE_VISIBILITY
   1521     explicit __alloc_func(_Target&& __f, _Alloc&& __a)
   1522         : __f_(piecewise_construct, _VSTD::forward_as_tuple(_VSTD::move(__f)),
   1523                _VSTD::forward_as_tuple(_VSTD::move(__a)))
   1524     {
   1525     }
   1526 
   1527     _LIBCPP_INLINE_VISIBILITY
   1528     _Rp operator()(_ArgTypes&&... __arg)
   1529     {
   1530         typedef __invoke_void_return_wrapper<_Rp> _Invoker;
   1531         return _Invoker::__call(__f_.first(),
   1532                                 _VSTD::forward<_ArgTypes>(__arg)...);
   1533     }
   1534 
   1535     _LIBCPP_INLINE_VISIBILITY
   1536     __alloc_func* __clone() const
   1537     {
   1538         typedef allocator_traits<_Alloc> __alloc_traits;
   1539         typedef
   1540             typename __rebind_alloc_helper<__alloc_traits, __alloc_func>::type
   1541                 _AA;
   1542         _AA __a(__f_.second());
   1543         typedef __allocator_destructor<_AA> _Dp;
   1544         unique_ptr<__alloc_func, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
   1545         ::new ((void*)__hold.get()) __alloc_func(__f_.first(), _Alloc(__a));
   1546         return __hold.release();
   1547     }
   1548 
   1549     _LIBCPP_INLINE_VISIBILITY
   1550     void destroy() _NOEXCEPT { __f_.~__compressed_pair<_Target, _Alloc>(); }
   1551 };
   1552 
   1553 // __base provides an abstract interface for copyable functors.
   1554 
   1555 template<class _Fp> class __base;
   1556 
   1557 template<class _Rp, class ..._ArgTypes>
   1558 class __base<_Rp(_ArgTypes...)>
   1559 {
   1560     __base(const __base&);
   1561     __base& operator=(const __base&);
   1562 public:
   1563     _LIBCPP_INLINE_VISIBILITY __base() {}
   1564     _LIBCPP_INLINE_VISIBILITY virtual ~__base() {}
   1565     virtual __base* __clone() const = 0;
   1566     virtual void __clone(__base*) const = 0;
   1567     virtual void destroy() _NOEXCEPT = 0;
   1568     virtual void destroy_deallocate() _NOEXCEPT = 0;
   1569     virtual _Rp operator()(_ArgTypes&& ...) = 0;
   1570 #ifndef _LIBCPP_NO_RTTI
   1571     virtual const void* target(const type_info&) const _NOEXCEPT = 0;
   1572     virtual const std::type_info& target_type() const _NOEXCEPT = 0;
   1573 #endif  // _LIBCPP_NO_RTTI
   1574 };
   1575 
   1576 // __func implements __base for a given functor type.
   1577 
   1578 template<class _FD, class _Alloc, class _FB> class __func;
   1579 
   1580 template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
   1581 class __func<_Fp, _Alloc, _Rp(_ArgTypes...)>
   1582     : public  __base<_Rp(_ArgTypes...)>
   1583 {
   1584     __alloc_func<_Fp, _Alloc, _Rp(_ArgTypes...)> __f_;
   1585 public:
   1586     _LIBCPP_INLINE_VISIBILITY
   1587     explicit __func(_Fp&& __f)
   1588         : __f_(_VSTD::move(__f)) {}
   1589 
   1590     _LIBCPP_INLINE_VISIBILITY
   1591     explicit __func(const _Fp& __f, const _Alloc& __a)
   1592         : __f_(__f, __a) {}
   1593 
   1594     _LIBCPP_INLINE_VISIBILITY
   1595     explicit __func(const _Fp& __f, _Alloc&& __a)
   1596         : __f_(__f, _VSTD::move(__a)) {}
   1597 
   1598     _LIBCPP_INLINE_VISIBILITY
   1599     explicit __func(_Fp&& __f, _Alloc&& __a)
   1600         : __f_(_VSTD::move(__f), _VSTD::move(__a)) {}
   1601 
   1602     virtual __base<_Rp(_ArgTypes...)>* __clone() const;
   1603     virtual void __clone(__base<_Rp(_ArgTypes...)>*) const;
   1604     virtual void destroy() _NOEXCEPT;
   1605     virtual void destroy_deallocate() _NOEXCEPT;
   1606     virtual _Rp operator()(_ArgTypes&&... __arg);
   1607 #ifndef _LIBCPP_NO_RTTI
   1608     virtual const void* target(const type_info&) const _NOEXCEPT;
   1609     virtual const std::type_info& target_type() const _NOEXCEPT;
   1610 #endif  // _LIBCPP_NO_RTTI
   1611 };
   1612 
   1613 template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
   1614 __base<_Rp(_ArgTypes...)>*
   1615 __func<_Fp, _Alloc, _Rp(_ArgTypes...)>::__clone() const
   1616 {
   1617     typedef allocator_traits<_Alloc> __alloc_traits;
   1618     typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
   1619     _Ap __a(__f_.__allocator());
   1620     typedef __allocator_destructor<_Ap> _Dp;
   1621     unique_ptr<__func, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
   1622     ::new ((void*)__hold.get()) __func(__f_.__target(), _Alloc(__a));
   1623     return __hold.release();
   1624 }
   1625 
   1626 template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
   1627 void
   1628 __func<_Fp, _Alloc, _Rp(_ArgTypes...)>::__clone(__base<_Rp(_ArgTypes...)>* __p) const
   1629 {
   1630     ::new (__p) __func(__f_.__target(), __f_.__allocator());
   1631 }
   1632 
   1633 template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
   1634 void
   1635 __func<_Fp, _Alloc, _Rp(_ArgTypes...)>::destroy() _NOEXCEPT
   1636 {
   1637     __f_.destroy();
   1638 }
   1639 
   1640 template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
   1641 void
   1642 __func<_Fp, _Alloc, _Rp(_ArgTypes...)>::destroy_deallocate() _NOEXCEPT
   1643 {
   1644     typedef allocator_traits<_Alloc> __alloc_traits;
   1645     typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
   1646     _Ap __a(__f_.__allocator());
   1647     __f_.destroy();
   1648     __a.deallocate(this, 1);
   1649 }
   1650 
   1651 template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
   1652 _Rp
   1653 __func<_Fp, _Alloc, _Rp(_ArgTypes...)>::operator()(_ArgTypes&& ... __arg)
   1654 {
   1655     return __f_(_VSTD::forward<_ArgTypes>(__arg)...);
   1656 }
   1657 
   1658 #ifndef _LIBCPP_NO_RTTI
   1659 
   1660 template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
   1661 const void*
   1662 __func<_Fp, _Alloc, _Rp(_ArgTypes...)>::target(const type_info& __ti) const _NOEXCEPT
   1663 {
   1664     if (__ti == typeid(_Fp))
   1665         return &__f_.__target();
   1666     return (const void*)0;
   1667 }
   1668 
   1669 template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
   1670 const std::type_info&
   1671 __func<_Fp, _Alloc, _Rp(_ArgTypes...)>::target_type() const _NOEXCEPT
   1672 {
   1673     return typeid(_Fp);
   1674 }
   1675 
   1676 #endif  // _LIBCPP_NO_RTTI
   1677 
   1678 // __value_func creates a value-type from a __func.
   1679 
   1680 template <class _Fp> class __value_func;
   1681 
   1682 template <class _Rp, class... _ArgTypes> class __value_func<_Rp(_ArgTypes...)>
   1683 {
   1684     typename aligned_storage<3 * sizeof(void*)>::type __buf_;
   1685 
   1686     typedef __base<_Rp(_ArgTypes...)> __func;
   1687     __func* __f_;
   1688 
   1689     _LIBCPP_NO_CFI static __func* __as_base(void* p)
   1690     {
   1691         return reinterpret_cast<__func*>(p);
   1692     }
   1693 
   1694   public:
   1695     _LIBCPP_INLINE_VISIBILITY
   1696     __value_func() _NOEXCEPT : __f_(0) {}
   1697 
   1698     template <class _Fp, class _Alloc>
   1699     _LIBCPP_INLINE_VISIBILITY __value_func(_Fp&& __f, const _Alloc __a)
   1700         : __f_(0)
   1701     {
   1702         typedef allocator_traits<_Alloc> __alloc_traits;
   1703         typedef __function::__func<_Fp, _Alloc, _Rp(_ArgTypes...)> _Fun;
   1704         typedef typename __rebind_alloc_helper<__alloc_traits, _Fun>::type
   1705             _FunAlloc;
   1706 
   1707         if (__function::__not_null(__f))
   1708         {
   1709             _FunAlloc __af(__a);
   1710             if (sizeof(_Fun) <= sizeof(__buf_) &&
   1711                 is_nothrow_copy_constructible<_Fp>::value &&
   1712                 is_nothrow_copy_constructible<_FunAlloc>::value)
   1713             {
   1714                 __f_ =
   1715                     ::new ((void*)&__buf_) _Fun(_VSTD::move(__f), _Alloc(__af));
   1716             }
   1717             else
   1718             {
   1719                 typedef __allocator_destructor<_FunAlloc> _Dp;
   1720                 unique_ptr<__func, _Dp> __hold(__af.allocate(1), _Dp(__af, 1));
   1721                 ::new ((void*)__hold.get()) _Fun(_VSTD::move(__f), _Alloc(__a));
   1722                 __f_ = __hold.release();
   1723             }
   1724         }
   1725     }
   1726 
   1727     _LIBCPP_INLINE_VISIBILITY
   1728     __value_func(const __value_func& __f)
   1729     {
   1730         if (__f.__f_ == 0)
   1731             __f_ = 0;
   1732         else if ((void*)__f.__f_ == &__f.__buf_)
   1733         {
   1734             __f_ = __as_base(&__buf_);
   1735             __f.__f_->__clone(__f_);
   1736         }
   1737         else
   1738             __f_ = __f.__f_->__clone();
   1739     }
   1740 
   1741     _LIBCPP_INLINE_VISIBILITY
   1742     __value_func(__value_func&& __f) _NOEXCEPT
   1743     {
   1744         if (__f.__f_ == 0)
   1745             __f_ = 0;
   1746         else if ((void*)__f.__f_ == &__f.__buf_)
   1747         {
   1748             __f_ = __as_base(&__buf_);
   1749             __f.__f_->__clone(__f_);
   1750         }
   1751         else
   1752         {
   1753             __f_ = __f.__f_;
   1754             __f.__f_ = 0;
   1755         }
   1756     }
   1757 
   1758     _LIBCPP_INLINE_VISIBILITY
   1759     ~__value_func()
   1760     {
   1761         if ((void*)__f_ == &__buf_)
   1762             __f_->destroy();
   1763         else if (__f_)
   1764             __f_->destroy_deallocate();
   1765     }
   1766 
   1767     _LIBCPP_INLINE_VISIBILITY
   1768     __value_func& operator=(__value_func&& __f)
   1769     {
   1770         *this = nullptr;
   1771         if (__f.__f_ == 0)
   1772             __f_ = 0;
   1773         else if ((void*)__f.__f_ == &__f.__buf_)
   1774         {
   1775             __f_ = __as_base(&__buf_);
   1776             __f.__f_->__clone(__f_);
   1777         }
   1778         else
   1779         {
   1780             __f_ = __f.__f_;
   1781             __f.__f_ = 0;
   1782         }
   1783         return *this;
   1784     }
   1785 
   1786     _LIBCPP_INLINE_VISIBILITY
   1787     __value_func& operator=(nullptr_t)
   1788     {
   1789         __func* __f = __f_;
   1790         __f_ = 0;
   1791         if ((void*)__f == &__buf_)
   1792             __f->destroy();
   1793         else if (__f)
   1794             __f->destroy_deallocate();
   1795         return *this;
   1796     }
   1797 
   1798     _LIBCPP_INLINE_VISIBILITY
   1799     _Rp operator()(_ArgTypes&&... __args) const
   1800     {
   1801         if (__f_ == 0)
   1802             __throw_bad_function_call();
   1803         return (*__f_)(_VSTD::forward<_ArgTypes>(__args)...);
   1804     }
   1805 
   1806     _LIBCPP_INLINE_VISIBILITY
   1807     void swap(__value_func& __f) _NOEXCEPT
   1808     {
   1809         if (&__f == this)
   1810             return;
   1811         if ((void*)__f_ == &__buf_ && (void*)__f.__f_ == &__f.__buf_)
   1812         {
   1813             typename aligned_storage<sizeof(__buf_)>::type __tempbuf;
   1814             __func* __t = __as_base(&__tempbuf);
   1815             __f_->__clone(__t);
   1816             __f_->destroy();
   1817             __f_ = 0;
   1818             __f.__f_->__clone(__as_base(&__buf_));
   1819             __f.__f_->destroy();
   1820             __f.__f_ = 0;
   1821             __f_ = __as_base(&__buf_);
   1822             __t->__clone(__as_base(&__f.__buf_));
   1823             __t->destroy();
   1824             __f.__f_ = __as_base(&__f.__buf_);
   1825         }
   1826         else if ((void*)__f_ == &__buf_)
   1827         {
   1828             __f_->__clone(__as_base(&__f.__buf_));
   1829             __f_->destroy();
   1830             __f_ = __f.__f_;
   1831             __f.__f_ = __as_base(&__f.__buf_);
   1832         }
   1833         else if ((void*)__f.__f_ == &__f.__buf_)
   1834         {
   1835             __f.__f_->__clone(__as_base(&__buf_));
   1836             __f.__f_->destroy();
   1837             __f.__f_ = __f_;
   1838             __f_ = __as_base(&__buf_);
   1839         }
   1840         else
   1841             _VSTD::swap(__f_, __f.__f_);
   1842     }
   1843 
   1844     _LIBCPP_INLINE_VISIBILITY
   1845     _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT { return __f_ != 0; }
   1846 
   1847 #ifndef _LIBCPP_NO_RTTI
   1848     _LIBCPP_INLINE_VISIBILITY
   1849     const std::type_info& target_type() const _NOEXCEPT
   1850     {
   1851         if (__f_ == 0)
   1852             return typeid(void);
   1853         return __f_->target_type();
   1854     }
   1855 
   1856     template <typename _Tp>
   1857     _LIBCPP_INLINE_VISIBILITY const _Tp* target() const _NOEXCEPT
   1858     {
   1859         if (__f_ == 0)
   1860             return 0;
   1861         return (const _Tp*)__f_->target(typeid(_Tp));
   1862     }
   1863 #endif // _LIBCPP_NO_RTTI
   1864 };
   1865 
   1866 // Storage for a functor object, to be used with __policy to manage copy and
   1867 // destruction.
   1868 union __policy_storage
   1869 {
   1870     mutable char __small[sizeof(void*) * 2];
   1871     void* __large;
   1872 };
   1873 
   1874 // True if _Fun can safely be held in __policy_storage.__small.
   1875 template <typename _Fun>
   1876 struct __use_small_storage
   1877     : public _VSTD::integral_constant<
   1878           bool, sizeof(_Fun) <= sizeof(__policy_storage) &&
   1879                     _LIBCPP_ALIGNOF(_Fun) <= _LIBCPP_ALIGNOF(__policy_storage) &&
   1880                     _VSTD::is_trivially_copy_constructible<_Fun>::value &&
   1881                     _VSTD::is_trivially_destructible<_Fun>::value> {};
   1882 
   1883 // Policy contains information about how to copy, destroy, and move the
   1884 // underlying functor. You can think of it as a vtable of sorts.
   1885 struct __policy
   1886 {
   1887     // Used to copy or destroy __large values. null for trivial objects.
   1888     void* (*const __clone)(const void*);
   1889     void (*const __destroy)(void*);
   1890 
   1891     // True if this is the null policy (no value).
   1892     const bool __is_null;
   1893 
   1894     // The target type. May be null if RTTI is disabled.
   1895     const std::type_info* const __type_info;
   1896 
   1897     // Returns a pointer to a static policy object suitable for the functor
   1898     // type.
   1899     template <typename _Fun>
   1900     _LIBCPP_INLINE_VISIBILITY static const __policy* __create()
   1901     {
   1902         return __choose_policy<_Fun>(__use_small_storage<_Fun>());
   1903     }
   1904 
   1905     _LIBCPP_INLINE_VISIBILITY
   1906     static const __policy* __create_empty()
   1907     {
   1908         static const _LIBCPP_CONSTEXPR __policy __policy_ = {nullptr, nullptr,
   1909                                                              true,
   1910 #ifndef _LIBCPP_NO_RTTI
   1911                                                              &typeid(void)
   1912 #else
   1913                                                              nullptr
   1914 #endif
   1915         };
   1916         return &__policy_;
   1917     }
   1918 
   1919   private:
   1920     template <typename _Fun> static void* __large_clone(const void* __s)
   1921     {
   1922         const _Fun* __f = static_cast<const _Fun*>(__s);
   1923         return __f->__clone();
   1924     }
   1925 
   1926     template <typename _Fun> static void __large_destroy(void* __s)
   1927     {
   1928         typedef allocator_traits<typename _Fun::_Alloc> __alloc_traits;
   1929         typedef typename __rebind_alloc_helper<__alloc_traits, _Fun>::type
   1930             _FunAlloc;
   1931         _Fun* __f = static_cast<_Fun*>(__s);
   1932         _FunAlloc __a(__f->__allocator());
   1933         __f->destroy();
   1934         __a.deallocate(__f, 1);
   1935     }
   1936 
   1937     template <typename _Fun>
   1938     _LIBCPP_INLINE_VISIBILITY static const __policy*
   1939         __choose_policy(/* is_small = */ false_type)
   1940     {
   1941         static const _LIBCPP_CONSTEXPR __policy __policy_ = {
   1942             &__large_clone<_Fun>, &__large_destroy<_Fun>, false,
   1943 #ifndef _LIBCPP_NO_RTTI
   1944             &typeid(typename _Fun::_Target)
   1945 #else
   1946             nullptr
   1947 #endif
   1948         };
   1949         return &__policy_;
   1950     }
   1951 
   1952     template <typename _Fun>
   1953     _LIBCPP_INLINE_VISIBILITY static const __policy*
   1954         __choose_policy(/* is_small = */ true_type)
   1955     {
   1956         static const _LIBCPP_CONSTEXPR __policy __policy_ = {
   1957             nullptr, nullptr, false,
   1958 #ifndef _LIBCPP_NO_RTTI
   1959             &typeid(typename _Fun::_Target)
   1960 #else
   1961             nullptr
   1962 #endif
   1963         };
   1964         return &__policy_;
   1965     }
   1966 };
   1967 
   1968 // Used to choose between perfect forwarding or pass-by-value. Pass-by-value is
   1969 // faster for types that can be passed in registers.
   1970 template <typename _Tp>
   1971 using __fast_forward =
   1972     typename _VSTD::conditional<_VSTD::is_scalar<_Tp>::value, _Tp, _Tp&&>::type;
   1973 
   1974 // __policy_invoker calls an instance of __alloc_func held in __policy_storage.
   1975 
   1976 template <class _Fp> struct __policy_invoker;
   1977 
   1978 template <class _Rp, class... _ArgTypes>
   1979 struct __policy_invoker<_Rp(_ArgTypes...)>
   1980 {
   1981     typedef _Rp (*__Call)(const __policy_storage*,
   1982                           __fast_forward<_ArgTypes>...);
   1983 
   1984     __Call __call_;
   1985 
   1986     // Creates an invoker that throws bad_function_call.
   1987     _LIBCPP_INLINE_VISIBILITY
   1988     __policy_invoker() : __call_(&__call_empty) {}
   1989 
   1990     // Creates an invoker that calls the given instance of __func.
   1991     template <typename _Fun>
   1992     _LIBCPP_INLINE_VISIBILITY static __policy_invoker __create()
   1993     {
   1994         return __policy_invoker(&__call_impl<_Fun>);
   1995     }
   1996 
   1997   private:
   1998     _LIBCPP_INLINE_VISIBILITY
   1999     explicit __policy_invoker(__Call __c) : __call_(__c) {}
   2000 
   2001     static _Rp __call_empty(const __policy_storage*,
   2002                             __fast_forward<_ArgTypes>...)
   2003     {
   2004         __throw_bad_function_call();
   2005     }
   2006 
   2007     template <typename _Fun>
   2008     static _Rp __call_impl(const __policy_storage* __buf,
   2009                            __fast_forward<_ArgTypes>... __args)
   2010     {
   2011         _Fun* __f = reinterpret_cast<_Fun*>(__use_small_storage<_Fun>::value
   2012                                                 ? &__buf->__small
   2013                                                 : __buf->__large);
   2014         return (*__f)(_VSTD::forward<_ArgTypes>(__args)...);
   2015     }
   2016 };
   2017 
   2018 // __policy_func uses a __policy and __policy_invoker to create a type-erased,
   2019 // copyable functor.
   2020 
   2021 template <class _Fp> class __policy_func;
   2022 
   2023 template <class _Rp, class... _ArgTypes> class __policy_func<_Rp(_ArgTypes...)>
   2024 {
   2025     // Inline storage for small objects.
   2026     __policy_storage __buf_;
   2027 
   2028     // Calls the value stored in __buf_. This could technically be part of
   2029     // policy, but storing it here eliminates a level of indirection inside
   2030     // operator().
   2031     typedef __function::__policy_invoker<_Rp(_ArgTypes...)> __invoker;
   2032     __invoker __invoker_;
   2033 
   2034     // The policy that describes how to move / copy / destroy __buf_. Never
   2035     // null, even if the function is empty.
   2036     const __policy* __policy_;
   2037 
   2038   public:
   2039     _LIBCPP_INLINE_VISIBILITY
   2040     __policy_func() : __policy_(__policy::__create_empty()) {}
   2041 
   2042     template <class _Fp, class _Alloc>
   2043     _LIBCPP_INLINE_VISIBILITY __policy_func(_Fp&& __f, const _Alloc& __a)
   2044         : __policy_(__policy::__create_empty())
   2045     {
   2046         typedef __alloc_func<_Fp, _Alloc, _Rp(_ArgTypes...)> _Fun;
   2047         typedef allocator_traits<_Alloc> __alloc_traits;
   2048         typedef typename __rebind_alloc_helper<__alloc_traits, _Fun>::type
   2049             _FunAlloc;
   2050 
   2051         if (__function::__not_null(__f))
   2052         {
   2053             __invoker_ = __invoker::template __create<_Fun>();
   2054             __policy_ = __policy::__create<_Fun>();
   2055 
   2056             _FunAlloc __af(__a);
   2057             if (__use_small_storage<_Fun>())
   2058             {
   2059                 ::new ((void*)&__buf_.__small)
   2060                     _Fun(_VSTD::move(__f), _Alloc(__af));
   2061             }
   2062             else
   2063             {
   2064                 typedef __allocator_destructor<_FunAlloc> _Dp;
   2065                 unique_ptr<_Fun, _Dp> __hold(__af.allocate(1), _Dp(__af, 1));
   2066                 ::new ((void*)__hold.get())
   2067                     _Fun(_VSTD::move(__f), _Alloc(__af));
   2068                 __buf_.__large = __hold.release();
   2069             }
   2070         }
   2071     }
   2072 
   2073     _LIBCPP_INLINE_VISIBILITY
   2074     __policy_func(const __policy_func& __f)
   2075         : __buf_(__f.__buf_), __invoker_(__f.__invoker_),
   2076           __policy_(__f.__policy_)
   2077     {
   2078         if (__policy_->__clone)
   2079             __buf_.__large = __policy_->__clone(__f.__buf_.__large);
   2080     }
   2081 
   2082     _LIBCPP_INLINE_VISIBILITY
   2083     __policy_func(__policy_func&& __f)
   2084         : __buf_(__f.__buf_), __invoker_(__f.__invoker_),
   2085           __policy_(__f.__policy_)
   2086     {
   2087         if (__policy_->__destroy)
   2088         {
   2089             __f.__policy_ = __policy::__create_empty();
   2090             __f.__invoker_ = __invoker();
   2091         }
   2092     }
   2093 
   2094     _LIBCPP_INLINE_VISIBILITY
   2095     ~__policy_func()
   2096     {
   2097         if (__policy_->__destroy)
   2098             __policy_->__destroy(__buf_.__large);
   2099     }
   2100 
   2101     _LIBCPP_INLINE_VISIBILITY
   2102     __policy_func& operator=(__policy_func&& __f)
   2103     {
   2104         *this = nullptr;
   2105         __buf_ = __f.__buf_;
   2106         __invoker_ = __f.__invoker_;
   2107         __policy_ = __f.__policy_;
   2108         __f.__policy_ = __policy::__create_empty();
   2109         __f.__invoker_ = __invoker();
   2110         return *this;
   2111     }
   2112 
   2113     _LIBCPP_INLINE_VISIBILITY
   2114     __policy_func& operator=(nullptr_t)
   2115     {
   2116         const __policy* __p = __policy_;
   2117         __policy_ = __policy::__create_empty();
   2118         __invoker_ = __invoker();
   2119         if (__p->__destroy)
   2120             __p->__destroy(__buf_.__large);
   2121         return *this;
   2122     }
   2123 
   2124     _LIBCPP_INLINE_VISIBILITY
   2125     _Rp operator()(_ArgTypes&&... __args) const
   2126     {
   2127         return __invoker_.__call_(_VSTD::addressof(__buf_),
   2128                                   _VSTD::forward<_ArgTypes>(__args)...);
   2129     }
   2130 
   2131     _LIBCPP_INLINE_VISIBILITY
   2132     void swap(__policy_func& __f)
   2133     {
   2134         _VSTD::swap(__invoker_, __f.__invoker_);
   2135         _VSTD::swap(__policy_, __f.__policy_);
   2136         _VSTD::swap(__buf_, __f.__buf_);
   2137     }
   2138 
   2139     _LIBCPP_INLINE_VISIBILITY
   2140     explicit operator bool() const _NOEXCEPT
   2141     {
   2142         return !__policy_->__is_null;
   2143     }
   2144 
   2145 #ifndef _LIBCPP_NO_RTTI
   2146     _LIBCPP_INLINE_VISIBILITY
   2147     const std::type_info& target_type() const _NOEXCEPT
   2148     {
   2149         return *__policy_->__type_info;
   2150     }
   2151 
   2152     template <typename _Tp>
   2153     _LIBCPP_INLINE_VISIBILITY const _Tp* target() const _NOEXCEPT
   2154     {
   2155         if (__policy_->__is_null || typeid(_Tp) != *__policy_->__type_info)
   2156             return nullptr;
   2157         if (__policy_->__clone) // Out of line storage.
   2158             return reinterpret_cast<const _Tp*>(__buf_.__large);
   2159         else
   2160             return reinterpret_cast<const _Tp*>(&__buf_.__small);
   2161     }
   2162 #endif // _LIBCPP_NO_RTTI
   2163 };
   2164 
   2165 }  // __function
   2166 
   2167 template<class _Rp, class ..._ArgTypes>
   2168 class _LIBCPP_TEMPLATE_VIS function<_Rp(_ArgTypes...)>
   2169     : public __function::__maybe_derive_from_unary_function<_Rp(_ArgTypes...)>,
   2170       public __function::__maybe_derive_from_binary_function<_Rp(_ArgTypes...)>
   2171 {
   2172 #ifndef _LIBCPP_ABI_OPTIMIZED_FUNCTION
   2173     typedef __function::__value_func<_Rp(_ArgTypes...)> __func;
   2174 #else
   2175     typedef __function::__policy_func<_Rp(_ArgTypes...)> __func;
   2176 #endif
   2177 
   2178     __func __f_;
   2179 
   2180     template <class _Fp, bool = __lazy_and<
   2181         integral_constant<bool, !is_same<__uncvref_t<_Fp>, function>::value>,
   2182         __invokable<_Fp&, _ArgTypes...>
   2183     >::value>
   2184     struct __callable;
   2185     template <class _Fp>
   2186         struct __callable<_Fp, true>
   2187         {
   2188             static const bool value = is_same<void, _Rp>::value ||
   2189                 is_convertible<typename __invoke_of<_Fp&, _ArgTypes...>::type,
   2190                                _Rp>::value;
   2191         };
   2192     template <class _Fp>
   2193         struct __callable<_Fp, false>
   2194         {
   2195             static const bool value = false;
   2196         };
   2197 
   2198   template <class _Fp>
   2199   using _EnableIfCallable = typename enable_if<__callable<_Fp>::value>::type;
   2200 public:
   2201     typedef _Rp result_type;
   2202 
   2203     // construct/copy/destroy:
   2204     _LIBCPP_INLINE_VISIBILITY
   2205     function() _NOEXCEPT { }
   2206     _LIBCPP_INLINE_VISIBILITY
   2207     function(nullptr_t) _NOEXCEPT {}
   2208     function(const function&);
   2209     function(function&&) _NOEXCEPT;
   2210     template<class _Fp, class = _EnableIfCallable<_Fp>>
   2211     function(_Fp);
   2212 
   2213 #if _LIBCPP_STD_VER <= 14
   2214     template<class _Alloc>
   2215       _LIBCPP_INLINE_VISIBILITY
   2216       function(allocator_arg_t, const _Alloc&) _NOEXCEPT {}
   2217     template<class _Alloc>
   2218       _LIBCPP_INLINE_VISIBILITY
   2219       function(allocator_arg_t, const _Alloc&, nullptr_t) _NOEXCEPT {}
   2220     template<class _Alloc>
   2221       function(allocator_arg_t, const _Alloc&, const function&);
   2222     template<class _Alloc>
   2223       function(allocator_arg_t, const _Alloc&, function&&);
   2224     template<class _Fp, class _Alloc, class = _EnableIfCallable<_Fp>>
   2225       function(allocator_arg_t, const _Alloc& __a, _Fp __f);
   2226 #endif
   2227 
   2228     function& operator=(const function&);
   2229     function& operator=(function&&) _NOEXCEPT;
   2230     function& operator=(nullptr_t) _NOEXCEPT;
   2231     template<class _Fp, class = _EnableIfCallable<_Fp>>
   2232     function& operator=(_Fp&&);
   2233 
   2234     ~function();
   2235 
   2236     // function modifiers:
   2237     void swap(function&) _NOEXCEPT;
   2238 
   2239 #if _LIBCPP_STD_VER <= 14
   2240     template<class _Fp, class _Alloc>
   2241       _LIBCPP_INLINE_VISIBILITY
   2242       void assign(_Fp&& __f, const _Alloc& __a)
   2243         {function(allocator_arg, __a, _VSTD::forward<_Fp>(__f)).swap(*this);}
   2244 #endif
   2245 
   2246     // function capacity:
   2247     _LIBCPP_INLINE_VISIBILITY
   2248     _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
   2249       return static_cast<bool>(__f_);
   2250     }
   2251 
   2252     // deleted overloads close possible hole in the type system
   2253     template<class _R2, class... _ArgTypes2>
   2254       bool operator==(const function<_R2(_ArgTypes2...)>&) const = delete;
   2255     template<class _R2, class... _ArgTypes2>
   2256       bool operator!=(const function<_R2(_ArgTypes2...)>&) const = delete;
   2257 public:
   2258     // function invocation:
   2259     _Rp operator()(_ArgTypes...) const;
   2260 
   2261 #ifndef _LIBCPP_NO_RTTI
   2262     // function target access:
   2263     const std::type_info& target_type() const _NOEXCEPT;
   2264     template <typename _Tp> _Tp* target() _NOEXCEPT;
   2265     template <typename _Tp> const _Tp* target() const _NOEXCEPT;
   2266 #endif  // _LIBCPP_NO_RTTI
   2267 };
   2268 
   2269 template<class _Rp, class ..._ArgTypes>
   2270 function<_Rp(_ArgTypes...)>::function(const function& __f) : __f_(__f.__f_) {}
   2271 
   2272 #if _LIBCPP_STD_VER <= 14
   2273 template<class _Rp, class ..._ArgTypes>
   2274 template <class _Alloc>
   2275 function<_Rp(_ArgTypes...)>::function(allocator_arg_t, const _Alloc&,
   2276                                      const function& __f) : __f_(__f.__f_) {}
   2277 #endif
   2278 
   2279 template <class _Rp, class... _ArgTypes>
   2280 function<_Rp(_ArgTypes...)>::function(function&& __f) _NOEXCEPT
   2281     : __f_(_VSTD::move(__f.__f_)) {}
   2282 
   2283 #if _LIBCPP_STD_VER <= 14
   2284 template<class _Rp, class ..._ArgTypes>
   2285 template <class _Alloc>
   2286 function<_Rp(_ArgTypes...)>::function(allocator_arg_t, const _Alloc&,
   2287                                       function&& __f)
   2288     : __f_(_VSTD::move(__f.__f_)) {}
   2289 #endif
   2290 
   2291 template <class _Rp, class... _ArgTypes>
   2292 template <class _Fp, class>
   2293 function<_Rp(_ArgTypes...)>::function(_Fp __f)
   2294     : __f_(_VSTD::move(__f), allocator<_Fp>()) {}
   2295 
   2296 #if _LIBCPP_STD_VER <= 14
   2297 template <class _Rp, class... _ArgTypes>
   2298 template <class _Fp, class _Alloc, class>
   2299 function<_Rp(_ArgTypes...)>::function(allocator_arg_t, const _Alloc& __a,
   2300                                       _Fp __f)
   2301     : __f_(_VSTD::move(__f), __a) {}
   2302 #endif
   2303 
   2304 template<class _Rp, class ..._ArgTypes>
   2305 function<_Rp(_ArgTypes...)>&
   2306 function<_Rp(_ArgTypes...)>::operator=(const function& __f)
   2307 {
   2308     function(__f).swap(*this);
   2309     return *this;
   2310 }
   2311 
   2312 template<class _Rp, class ..._ArgTypes>
   2313 function<_Rp(_ArgTypes...)>&
   2314 function<_Rp(_ArgTypes...)>::operator=(function&& __f) _NOEXCEPT
   2315 {
   2316     __f_ = std::move(__f.__f_);
   2317     return *this;
   2318 }
   2319 
   2320 template<class _Rp, class ..._ArgTypes>
   2321 function<_Rp(_ArgTypes...)>&
   2322 function<_Rp(_ArgTypes...)>::operator=(nullptr_t) _NOEXCEPT
   2323 {
   2324     __f_ = nullptr;
   2325     return *this;
   2326 }
   2327 
   2328 template<class _Rp, class ..._ArgTypes>
   2329 template <class _Fp, class>
   2330 function<_Rp(_ArgTypes...)>&
   2331 function<_Rp(_ArgTypes...)>::operator=(_Fp&& __f)
   2332 {
   2333     function(_VSTD::forward<_Fp>(__f)).swap(*this);
   2334     return *this;
   2335 }
   2336 
   2337 template<class _Rp, class ..._ArgTypes>
   2338 function<_Rp(_ArgTypes...)>::~function() {}
   2339 
   2340 template<class _Rp, class ..._ArgTypes>
   2341 void
   2342 function<_Rp(_ArgTypes...)>::swap(function& __f) _NOEXCEPT
   2343 {
   2344     __f_.swap(__f.__f_);
   2345 }
   2346 
   2347 template<class _Rp, class ..._ArgTypes>
   2348 _Rp
   2349 function<_Rp(_ArgTypes...)>::operator()(_ArgTypes... __arg) const
   2350 {
   2351     return __f_(_VSTD::forward<_ArgTypes>(__arg)...);
   2352 }
   2353 
   2354 #ifndef _LIBCPP_NO_RTTI
   2355 
   2356 template<class _Rp, class ..._ArgTypes>
   2357 const std::type_info&
   2358 function<_Rp(_ArgTypes...)>::target_type() const _NOEXCEPT
   2359 {
   2360     return __f_.target_type();
   2361 }
   2362 
   2363 template<class _Rp, class ..._ArgTypes>
   2364 template <typename _Tp>
   2365 _Tp*
   2366 function<_Rp(_ArgTypes...)>::target() _NOEXCEPT
   2367 {
   2368     return (_Tp*)(__f_.template target<_Tp>());
   2369 }
   2370 
   2371 template<class _Rp, class ..._ArgTypes>
   2372 template <typename _Tp>
   2373 const _Tp*
   2374 function<_Rp(_ArgTypes...)>::target() const _NOEXCEPT
   2375 {
   2376     return __f_.template target<_Tp>();
   2377 }
   2378 
   2379 #endif  // _LIBCPP_NO_RTTI
   2380 
   2381 template <class _Rp, class... _ArgTypes>
   2382 inline _LIBCPP_INLINE_VISIBILITY
   2383 bool
   2384 operator==(const function<_Rp(_ArgTypes...)>& __f, nullptr_t) _NOEXCEPT {return !__f;}
   2385 
   2386 template <class _Rp, class... _ArgTypes>
   2387 inline _LIBCPP_INLINE_VISIBILITY
   2388 bool
   2389 operator==(nullptr_t, const function<_Rp(_ArgTypes...)>& __f) _NOEXCEPT {return !__f;}
   2390 
   2391 template <class _Rp, class... _ArgTypes>
   2392 inline _LIBCPP_INLINE_VISIBILITY
   2393 bool
   2394 operator!=(const function<_Rp(_ArgTypes...)>& __f, nullptr_t) _NOEXCEPT {return (bool)__f;}
   2395 
   2396 template <class _Rp, class... _ArgTypes>
   2397 inline _LIBCPP_INLINE_VISIBILITY
   2398 bool
   2399 operator!=(nullptr_t, const function<_Rp(_ArgTypes...)>& __f) _NOEXCEPT {return (bool)__f;}
   2400 
   2401 template <class _Rp, class... _ArgTypes>
   2402 inline _LIBCPP_INLINE_VISIBILITY
   2403 void
   2404 swap(function<_Rp(_ArgTypes...)>& __x, function<_Rp(_ArgTypes...)>& __y) _NOEXCEPT
   2405 {return __x.swap(__y);}
   2406 
   2407 #else // _LIBCPP_CXX03_LANG
   2408 
   2409 #include <__functional_03>
   2410 
   2411 #endif
   2412 
   2413 ////////////////////////////////////////////////////////////////////////////////
   2414 //                                  BIND
   2415 //==============================================================================
   2416 
   2417 template<class _Tp> struct __is_bind_expression : public false_type {};
   2418 template<class _Tp> struct _LIBCPP_TEMPLATE_VIS is_bind_expression
   2419     : public __is_bind_expression<typename remove_cv<_Tp>::type> {};
   2420 
   2421 #if _LIBCPP_STD_VER > 14
   2422 template <class _Tp>
   2423 _LIBCPP_INLINE_VAR constexpr size_t is_bind_expression_v = is_bind_expression<_Tp>::value;
   2424 #endif
   2425 
   2426 template<class _Tp> struct __is_placeholder : public integral_constant<int, 0> {};
   2427 template<class _Tp> struct _LIBCPP_TEMPLATE_VIS is_placeholder
   2428     : public __is_placeholder<typename remove_cv<_Tp>::type> {};
   2429 
   2430 #if _LIBCPP_STD_VER > 14
   2431 template <class _Tp>
   2432 _LIBCPP_INLINE_VAR constexpr size_t is_placeholder_v = is_placeholder<_Tp>::value;
   2433 #endif
   2434 
   2435 namespace placeholders
   2436 {
   2437 
   2438 template <int _Np> struct __ph {};
   2439 
   2440 #if defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_LIBRARY)
   2441 _LIBCPP_FUNC_VIS extern const __ph<1>   _1;
   2442 _LIBCPP_FUNC_VIS extern const __ph<2>   _2;
   2443 _LIBCPP_FUNC_VIS extern const __ph<3>   _3;
   2444 _LIBCPP_FUNC_VIS extern const __ph<4>   _4;
   2445 _LIBCPP_FUNC_VIS extern const __ph<5>   _5;
   2446 _LIBCPP_FUNC_VIS extern const __ph<6>   _6;
   2447 _LIBCPP_FUNC_VIS extern const __ph<7>   _7;
   2448 _LIBCPP_FUNC_VIS extern const __ph<8>   _8;
   2449 _LIBCPP_FUNC_VIS extern const __ph<9>   _9;
   2450 _LIBCPP_FUNC_VIS extern const __ph<10> _10;
   2451 #else
   2452 /* _LIBCPP_INLINE_VAR */ constexpr __ph<1>   _1{};
   2453 /* _LIBCPP_INLINE_VAR */ constexpr __ph<2>   _2{};
   2454 /* _LIBCPP_INLINE_VAR */ constexpr __ph<3>   _3{};
   2455 /* _LIBCPP_INLINE_VAR */ constexpr __ph<4>   _4{};
   2456 /* _LIBCPP_INLINE_VAR */ constexpr __ph<5>   _5{};
   2457 /* _LIBCPP_INLINE_VAR */ constexpr __ph<6>   _6{};
   2458 /* _LIBCPP_INLINE_VAR */ constexpr __ph<7>   _7{};
   2459 /* _LIBCPP_INLINE_VAR */ constexpr __ph<8>   _8{};
   2460 /* _LIBCPP_INLINE_VAR */ constexpr __ph<9>   _9{};
   2461 /* _LIBCPP_INLINE_VAR */ constexpr __ph<10> _10{};
   2462 #endif // defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_LIBRARY)
   2463 
   2464 }  // placeholders
   2465 
   2466 template<int _Np>
   2467 struct __is_placeholder<placeholders::__ph<_Np> >
   2468     : public integral_constant<int, _Np> {};
   2469 
   2470 
   2471 #ifndef _LIBCPP_CXX03_LANG
   2472 
   2473 template <class _Tp, class _Uj>
   2474 inline _LIBCPP_INLINE_VISIBILITY
   2475 _Tp&
   2476 __mu(reference_wrapper<_Tp> __t, _Uj&)
   2477 {
   2478     return __t.get();
   2479 }
   2480 
   2481 template <class _Ti, class ..._Uj, size_t ..._Indx>
   2482 inline _LIBCPP_INLINE_VISIBILITY
   2483 typename __invoke_of<_Ti&, _Uj...>::type
   2484 __mu_expand(_Ti& __ti, tuple<_Uj...>& __uj, __tuple_indices<_Indx...>)
   2485 {
   2486     return __ti(_VSTD::forward<_Uj>(_VSTD::get<_Indx>(__uj))...);
   2487 }
   2488 
   2489 template <class _Ti, class ..._Uj>
   2490 inline _LIBCPP_INLINE_VISIBILITY
   2491 typename __lazy_enable_if
   2492 <
   2493     is_bind_expression<_Ti>::value,
   2494     __invoke_of<_Ti&, _Uj...>
   2495 >::type
   2496 __mu(_Ti& __ti, tuple<_Uj...>& __uj)
   2497 {
   2498     typedef typename __make_tuple_indices<sizeof...(_Uj)>::type __indices;
   2499     return  __mu_expand(__ti, __uj, __indices());
   2500 }
   2501 
   2502 template <bool IsPh, class _Ti, class _Uj>
   2503 struct __mu_return2 {};
   2504 
   2505 template <class _Ti, class _Uj>
   2506 struct __mu_return2<true, _Ti, _Uj>
   2507 {
   2508     typedef typename tuple_element<is_placeholder<_Ti>::value - 1, _Uj>::type type;
   2509 };
   2510 
   2511 template <class _Ti, class _Uj>
   2512 inline _LIBCPP_INLINE_VISIBILITY
   2513 typename enable_if
   2514 <
   2515     0 < is_placeholder<_Ti>::value,
   2516     typename __mu_return2<0 < is_placeholder<_Ti>::value, _Ti, _Uj>::type
   2517 >::type
   2518 __mu(_Ti&, _Uj& __uj)
   2519 {
   2520     const size_t _Indx = is_placeholder<_Ti>::value - 1;
   2521     return _VSTD::forward<typename tuple_element<_Indx, _Uj>::type>(_VSTD::get<_Indx>(__uj));
   2522 }
   2523 
   2524 template <class _Ti, class _Uj>
   2525 inline _LIBCPP_INLINE_VISIBILITY
   2526 typename enable_if
   2527 <
   2528     !is_bind_expression<_Ti>::value &&
   2529     is_placeholder<_Ti>::value == 0 &&
   2530     !__is_reference_wrapper<_Ti>::value,
   2531     _Ti&
   2532 >::type
   2533 __mu(_Ti& __ti, _Uj&)
   2534 {
   2535     return __ti;
   2536 }
   2537 
   2538 template <class _Ti, bool IsReferenceWrapper, bool IsBindEx, bool IsPh,
   2539           class _TupleUj>
   2540 struct __mu_return_impl;
   2541 
   2542 template <bool _Invokable, class _Ti, class ..._Uj>
   2543 struct __mu_return_invokable  // false
   2544 {
   2545     typedef __nat type;
   2546 };
   2547 
   2548 template <class _Ti, class ..._Uj>
   2549 struct __mu_return_invokable<true, _Ti, _Uj...>
   2550 {
   2551     typedef typename __invoke_of<_Ti&, _Uj...>::type type;
   2552 };
   2553 
   2554 template <class _Ti, class ..._Uj>
   2555 struct __mu_return_impl<_Ti, false, true, false, tuple<_Uj...> >
   2556     : public __mu_return_invokable<__invokable<_Ti&, _Uj...>::value, _Ti, _Uj...>
   2557 {
   2558 };
   2559 
   2560 template <class _Ti, class _TupleUj>
   2561 struct __mu_return_impl<_Ti, false, false, true, _TupleUj>
   2562 {
   2563     typedef typename tuple_element<is_placeholder<_Ti>::value - 1,
   2564                                    _TupleUj>::type&& type;
   2565 };
   2566 
   2567 template <class _Ti, class _TupleUj>
   2568 struct __mu_return_impl<_Ti, true, false, false, _TupleUj>
   2569 {
   2570     typedef typename _Ti::type& type;
   2571 };
   2572 
   2573 template <class _Ti, class _TupleUj>
   2574 struct __mu_return_impl<_Ti, false, false, false, _TupleUj>
   2575 {
   2576     typedef _Ti& type;
   2577 };
   2578 
   2579 template <class _Ti, class _TupleUj>
   2580 struct __mu_return
   2581     : public __mu_return_impl<_Ti,
   2582                               __is_reference_wrapper<_Ti>::value,
   2583                               is_bind_expression<_Ti>::value,
   2584                               0 < is_placeholder<_Ti>::value &&
   2585                               is_placeholder<_Ti>::value <= tuple_size<_TupleUj>::value,
   2586                               _TupleUj>
   2587 {
   2588 };
   2589 
   2590 template <class _Fp, class _BoundArgs, class _TupleUj>
   2591 struct __is_valid_bind_return
   2592 {
   2593     static const bool value = false;
   2594 };
   2595 
   2596 template <class _Fp, class ..._BoundArgs, class _TupleUj>
   2597 struct __is_valid_bind_return<_Fp, tuple<_BoundArgs...>, _TupleUj>
   2598 {
   2599     static const bool value = __invokable<_Fp,
   2600                     typename __mu_return<_BoundArgs, _TupleUj>::type...>::value;
   2601 };
   2602 
   2603 template <class _Fp, class ..._BoundArgs, class _TupleUj>
   2604 struct __is_valid_bind_return<_Fp, const tuple<_BoundArgs...>, _TupleUj>
   2605 {
   2606     static const bool value = __invokable<_Fp,
   2607                     typename __mu_return<const _BoundArgs, _TupleUj>::type...>::value;
   2608 };
   2609 
   2610 template <class _Fp, class _BoundArgs, class _TupleUj,
   2611           bool = __is_valid_bind_return<_Fp, _BoundArgs, _TupleUj>::value>
   2612 struct __bind_return;
   2613 
   2614 template <class _Fp, class ..._BoundArgs, class _TupleUj>
   2615 struct __bind_return<_Fp, tuple<_BoundArgs...>, _TupleUj, true>
   2616 {
   2617     typedef typename __invoke_of
   2618     <
   2619         _Fp&,
   2620         typename __mu_return
   2621         <
   2622             _BoundArgs,
   2623             _TupleUj
   2624         >::type...
   2625     >::type type;
   2626 };
   2627 
   2628 template <class _Fp, class ..._BoundArgs, class _TupleUj>
   2629 struct __bind_return<_Fp, const tuple<_BoundArgs...>, _TupleUj, true>
   2630 {
   2631     typedef typename __invoke_of
   2632     <
   2633         _Fp&,
   2634         typename __mu_return
   2635         <
   2636             const _BoundArgs,
   2637             _TupleUj
   2638         >::type...
   2639     >::type type;
   2640 };
   2641 
   2642 template <class _Fp, class _BoundArgs, size_t ..._Indx, class _Args>
   2643 inline _LIBCPP_INLINE_VISIBILITY
   2644 typename __bind_return<_Fp, _BoundArgs, _Args>::type
   2645 __apply_functor(_Fp& __f, _BoundArgs& __bound_args, __tuple_indices<_Indx...>,
   2646                 _Args&& __args)
   2647 {
   2648     return _VSTD::__invoke(__f, _VSTD::__mu(_VSTD::get<_Indx>(__bound_args), __args)...);
   2649 }
   2650 
   2651 template<class _Fp, class ..._BoundArgs>
   2652 class __bind
   2653     : public __weak_result_type<typename decay<_Fp>::type>
   2654 {
   2655 protected:
   2656     typedef typename decay<_Fp>::type _Fd;
   2657     typedef tuple<typename decay<_BoundArgs>::type...> _Td;
   2658 private:
   2659     _Fd __f_;
   2660     _Td __bound_args_;
   2661 
   2662     typedef typename __make_tuple_indices<sizeof...(_BoundArgs)>::type __indices;
   2663 public:
   2664     template <class _Gp, class ..._BA,
   2665               class = typename enable_if
   2666                                <
   2667                                   is_constructible<_Fd, _Gp>::value &&
   2668                                   !is_same<typename remove_reference<_Gp>::type,
   2669                                            __bind>::value
   2670                                >::type>
   2671       _LIBCPP_INLINE_VISIBILITY
   2672       explicit __bind(_Gp&& __f, _BA&& ...__bound_args)
   2673         : __f_(_VSTD::forward<_Gp>(__f)),
   2674           __bound_args_(_VSTD::forward<_BA>(__bound_args)...) {}
   2675 
   2676     template <class ..._Args>
   2677         _LIBCPP_INLINE_VISIBILITY
   2678         typename __bind_return<_Fd, _Td, tuple<_Args&&...> >::type
   2679         operator()(_Args&& ...__args)
   2680         {
   2681             return _VSTD::__apply_functor(__f_, __bound_args_, __indices(),
   2682                                   tuple<_Args&&...>(_VSTD::forward<_Args>(__args)...));
   2683         }
   2684 
   2685     template <class ..._Args>
   2686         _LIBCPP_INLINE_VISIBILITY
   2687         typename __bind_return<const _Fd, const _Td, tuple<_Args&&...> >::type
   2688         operator()(_Args&& ...__args) const
   2689         {
   2690             return _VSTD::__apply_functor(__f_, __bound_args_, __indices(),
   2691                                    tuple<_Args&&...>(_VSTD::forward<_Args>(__args)...));
   2692         }
   2693 };
   2694 
   2695 template<class _Fp, class ..._BoundArgs>
   2696 struct __is_bind_expression<__bind<_Fp, _BoundArgs...> > : public true_type {};
   2697 
   2698 template<class _Rp, class _Fp, class ..._BoundArgs>
   2699 class __bind_r
   2700     : public __bind<_Fp, _BoundArgs...>
   2701 {
   2702     typedef __bind<_Fp, _BoundArgs...> base;
   2703     typedef typename base::_Fd _Fd;
   2704     typedef typename base::_Td _Td;
   2705 public:
   2706     typedef _Rp result_type;
   2707 
   2708 
   2709     template <class _Gp, class ..._BA,
   2710               class = typename enable_if
   2711                                <
   2712                                   is_constructible<_Fd, _Gp>::value &&
   2713                                   !is_same<typename remove_reference<_Gp>::type,
   2714                                            __bind_r>::value
   2715                                >::type>
   2716       _LIBCPP_INLINE_VISIBILITY
   2717       explicit __bind_r(_Gp&& __f, _BA&& ...__bound_args)
   2718         : base(_VSTD::forward<_Gp>(__f),
   2719                _VSTD::forward<_BA>(__bound_args)...) {}
   2720 
   2721     template <class ..._Args>
   2722         _LIBCPP_INLINE_VISIBILITY
   2723         typename enable_if
   2724         <
   2725             is_convertible<typename __bind_return<_Fd, _Td, tuple<_Args&&...> >::type,
   2726                            result_type>::value || is_void<_Rp>::value,
   2727             result_type
   2728         >::type
   2729         operator()(_Args&& ...__args)
   2730         {
   2731             typedef __invoke_void_return_wrapper<_Rp> _Invoker;
   2732             return _Invoker::__call(static_cast<base&>(*this), _VSTD::forward<_Args>(__args)...);
   2733         }
   2734 
   2735     template <class ..._Args>
   2736         _LIBCPP_INLINE_VISIBILITY
   2737         typename enable_if
   2738         <
   2739             is_convertible<typename __bind_return<const _Fd, const _Td, tuple<_Args&&...> >::type,
   2740                            result_type>::value || is_void<_Rp>::value,
   2741             result_type
   2742         >::type
   2743         operator()(_Args&& ...__args) const
   2744         {
   2745             typedef __invoke_void_return_wrapper<_Rp> _Invoker;
   2746             return _Invoker::__call(static_cast<base const&>(*this), _VSTD::forward<_Args>(__args)...);
   2747         }
   2748 };
   2749 
   2750 template<class _Rp, class _Fp, class ..._BoundArgs>
   2751 struct __is_bind_expression<__bind_r<_Rp, _Fp, _BoundArgs...> > : public true_type {};
   2752 
   2753 template<class _Fp, class ..._BoundArgs>
   2754 inline _LIBCPP_INLINE_VISIBILITY
   2755 __bind<_Fp, _BoundArgs...>
   2756 bind(_Fp&& __f, _BoundArgs&&... __bound_args)
   2757 {
   2758     typedef __bind<_Fp, _BoundArgs...> type;
   2759     return type(_VSTD::forward<_Fp>(__f), _VSTD::forward<_BoundArgs>(__bound_args)...);
   2760 }
   2761 
   2762 template<class _Rp, class _Fp, class ..._BoundArgs>
   2763 inline _LIBCPP_INLINE_VISIBILITY
   2764 __bind_r<_Rp, _Fp, _BoundArgs...>
   2765 bind(_Fp&& __f, _BoundArgs&&... __bound_args)
   2766 {
   2767     typedef __bind_r<_Rp, _Fp, _BoundArgs...> type;
   2768     return type(_VSTD::forward<_Fp>(__f), _VSTD::forward<_BoundArgs>(__bound_args)...);
   2769 }
   2770 
   2771 #endif  // _LIBCPP_CXX03_LANG
   2772 
   2773 #if _LIBCPP_STD_VER > 14
   2774 
   2775 template <class _Fn, class ..._Args>
   2776 result_of_t<_Fn&&(_Args&&...)>
   2777 invoke(_Fn&& __f, _Args&&... __args)
   2778     noexcept(noexcept(_VSTD::__invoke(_VSTD::forward<_Fn>(__f), _VSTD::forward<_Args>(__args)...)))
   2779 {
   2780     return _VSTD::__invoke(_VSTD::forward<_Fn>(__f), _VSTD::forward<_Args>(__args)...);
   2781 }
   2782 
   2783 template <class _DecayFunc>
   2784 class _LIBCPP_TEMPLATE_VIS __not_fn_imp {
   2785   _DecayFunc __fd;
   2786 
   2787 public:
   2788     __not_fn_imp() = delete;
   2789 
   2790     template <class ..._Args>
   2791     _LIBCPP_INLINE_VISIBILITY
   2792     auto operator()(_Args&& ...__args) &
   2793             noexcept(noexcept(!_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...)))
   2794         -> decltype(          !_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...))
   2795         { return              !_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...); }
   2796 
   2797     template <class ..._Args>
   2798     _LIBCPP_INLINE_VISIBILITY
   2799     auto operator()(_Args&& ...__args) &&
   2800             noexcept(noexcept(!_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...)))
   2801         -> decltype(          !_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...))
   2802         { return              !_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...); }
   2803 
   2804     template <class ..._Args>
   2805     _LIBCPP_INLINE_VISIBILITY
   2806     auto operator()(_Args&& ...__args) const&
   2807             noexcept(noexcept(!_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...)))
   2808         -> decltype(          !_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...))
   2809         { return              !_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...); }
   2810 
   2811 
   2812     template <class ..._Args>
   2813     _LIBCPP_INLINE_VISIBILITY
   2814     auto operator()(_Args&& ...__args) const&&
   2815             noexcept(noexcept(!_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...)))
   2816         -> decltype(          !_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...))
   2817         { return              !_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...); }
   2818 
   2819 private:
   2820     template <class _RawFunc,
   2821               class = enable_if_t<!is_same<decay_t<_RawFunc>, __not_fn_imp>::value>>
   2822     _LIBCPP_INLINE_VISIBILITY
   2823     explicit __not_fn_imp(_RawFunc&& __rf)
   2824         : __fd(_VSTD::forward<_RawFunc>(__rf)) {}
   2825 
   2826     template <class _RawFunc>
   2827     friend inline _LIBCPP_INLINE_VISIBILITY
   2828     __not_fn_imp<decay_t<_RawFunc>> not_fn(_RawFunc&&);
   2829 };
   2830 
   2831 template <class _RawFunc>
   2832 inline _LIBCPP_INLINE_VISIBILITY
   2833 __not_fn_imp<decay_t<_RawFunc>> not_fn(_RawFunc&& __fn) {
   2834     return __not_fn_imp<decay_t<_RawFunc>>(_VSTD::forward<_RawFunc>(__fn));
   2835 }
   2836 
   2837 #endif
   2838 
   2839 // struct hash<T*> in <memory>
   2840 
   2841 template <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
   2842 pair<_ForwardIterator1, _ForwardIterator1> _LIBCPP_CONSTEXPR_AFTER_CXX11
   2843 __search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
   2844          _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred,
   2845          forward_iterator_tag, forward_iterator_tag)
   2846 {
   2847     if (__first2 == __last2)
   2848         return make_pair(__first1, __first1);  // Everything matches an empty sequence
   2849     while (true)
   2850     {
   2851         // Find first element in sequence 1 that matchs *__first2, with a mininum of loop checks
   2852         while (true)
   2853         {
   2854             if (__first1 == __last1)  // return __last1 if no element matches *__first2
   2855                 return make_pair(__last1, __last1);
   2856             if (__pred(*__first1, *__first2))
   2857                 break;
   2858             ++__first1;
   2859         }
   2860         // *__first1 matches *__first2, now match elements after here
   2861         _ForwardIterator1 __m1 = __first1;
   2862         _ForwardIterator2 __m2 = __first2;
   2863         while (true)
   2864         {
   2865             if (++__m2 == __last2)  // If pattern exhausted, __first1 is the answer (works for 1 element pattern)
   2866                 return make_pair(__first1, __m1);
   2867             if (++__m1 == __last1)  // Otherwise if source exhaused, pattern not found
   2868                 return make_pair(__last1, __last1);
   2869             if (!__pred(*__m1, *__m2))  // if there is a mismatch, restart with a new __first1
   2870             {
   2871                 ++__first1;
   2872                 break;
   2873             }  // else there is a match, check next elements
   2874         }
   2875     }
   2876 }
   2877 
   2878 template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
   2879 _LIBCPP_CONSTEXPR_AFTER_CXX11
   2880 pair<_RandomAccessIterator1, _RandomAccessIterator1>
   2881 __search(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
   2882          _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
   2883            random_access_iterator_tag, random_access_iterator_tag)
   2884 {
   2885     typedef typename iterator_traits<_RandomAccessIterator1>::difference_type _D1;
   2886     typedef typename iterator_traits<_RandomAccessIterator2>::difference_type _D2;
   2887     // Take advantage of knowing source and pattern lengths.  Stop short when source is smaller than pattern
   2888     const _D2 __len2 = __last2 - __first2;
   2889     if (__len2 == 0)
   2890         return make_pair(__first1, __first1);
   2891     const _D1 __len1 = __last1 - __first1;
   2892     if (__len1 < __len2)
   2893         return make_pair(__last1, __last1);
   2894     const _RandomAccessIterator1 __s = __last1 - (__len2 - 1);  // Start of pattern match can't go beyond here
   2895 
   2896     while (true)
   2897     {
   2898         while (true)
   2899         {
   2900             if (__first1 == __s)
   2901                 return make_pair(__last1, __last1);
   2902             if (__pred(*__first1, *__first2))
   2903                 break;
   2904             ++__first1;
   2905         }
   2906 
   2907         _RandomAccessIterator1 __m1 = __first1;
   2908         _RandomAccessIterator2 __m2 = __first2;
   2909          while (true)
   2910          {
   2911              if (++__m2 == __last2)
   2912                  return make_pair(__first1, __first1 + __len2);
   2913              ++__m1;          // no need to check range on __m1 because __s guarantees we have enough source
   2914              if (!__pred(*__m1, *__m2))
   2915              {
   2916                  ++__first1;
   2917                  break;
   2918              }
   2919          }
   2920     }
   2921 }
   2922 
   2923 #if _LIBCPP_STD_VER > 14
   2924 
   2925 // default searcher
   2926 template<class _ForwardIterator, class _BinaryPredicate = equal_to<>>
   2927 class _LIBCPP_TYPE_VIS default_searcher {
   2928 public:
   2929     _LIBCPP_INLINE_VISIBILITY
   2930     default_searcher(_ForwardIterator __f, _ForwardIterator __l,
   2931                        _BinaryPredicate __p = _BinaryPredicate())
   2932         : __first_(__f), __last_(__l), __pred_(__p) {}
   2933 
   2934     template <typename _ForwardIterator2>
   2935     _LIBCPP_INLINE_VISIBILITY
   2936     pair<_ForwardIterator2, _ForwardIterator2>
   2937     operator () (_ForwardIterator2 __f, _ForwardIterator2 __l) const
   2938     {
   2939         return _VSTD::__search(__f, __l, __first_, __last_, __pred_,
   2940             typename _VSTD::iterator_traits<_ForwardIterator>::iterator_category(),
   2941             typename _VSTD::iterator_traits<_ForwardIterator2>::iterator_category());
   2942     }
   2943 
   2944 private:
   2945     _ForwardIterator __first_;
   2946     _ForwardIterator __last_;
   2947     _BinaryPredicate __pred_;
   2948     };
   2949 
   2950 #endif // _LIBCPP_STD_VER > 14
   2951 
   2952 #if _LIBCPP_STD_VER > 17
   2953 template <class _Tp>
   2954 using unwrap_reference_t = typename unwrap_reference<_Tp>::type;
   2955 
   2956 template <class _Tp>
   2957 using unwrap_ref_decay_t = typename unwrap_ref_decay<_Tp>::type;
   2958 #endif // > C++17
   2959 
   2960 template <class _Container, class _Predicate>
   2961 inline void __libcpp_erase_if_container( _Container& __c, _Predicate __pred)
   2962 {
   2963 	for (typename _Container::iterator __iter = __c.begin(), __last = __c.end(); __iter != __last;)
   2964 	{
   2965 		if (__pred(*__iter))
   2966 			__iter = __c.erase(__iter);
   2967 		else
   2968 			++__iter;
   2969 	}
   2970 }
   2971 
   2972 _LIBCPP_END_NAMESPACE_STD
   2973 
   2974 #endif  // _LIBCPP_FUNCTIONAL