/*  Copyright (C) 2015  Povilas Kanapickas <povilas@radix.lt>

    This file is part of cppreference-doc

    This work is licensed under the Creative Commons Attribution-ShareAlike 3.0
    Unported License. To view a copy of this license, visit
    http://creativecommons.org/licenses/by-sa/3.0/ or send a letter to Creative
    Commons, 444 Castro Street, Suite 900, Mountain View, California, 94041, USA.

    Permission is granted to copy, distribute and/or modify this document
    under the terms of the GNU Free Documentation License, Version 1.3 or
    any later version published by the Free Software Foundation; with no
    Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
*/

#ifndef CPPREFERENCE_FUNCTIONAL_H
#define CPPREFERENCE_FUNCTIONAL_H

namespace std {

#if CPPREFERENCE_STDVER >= 2011
template<class R, class... Args>
class function<R(Args...)> {
public:
    typedef R result_type;
    function();
    function(std::nullptr_t);
    function(const function& other);
    function(function&& other);
    template<class F >
    function(F f);
    template<class Alloc >
    function(std::allocator_arg_t, const Alloc& alloc);

    template<class Alloc >
    function(std::allocator_arg_t, const Alloc& alloc,
             std::nullptr_t);

    template<class Alloc >
    function(std::allocator_arg_t, const Alloc& alloc,
             const function& other);

    template<class Alloc >
    function(std::allocator_arg_t, const Alloc& alloc,
             function&& other);

    template<class F, class Alloc >
    function(std::allocator_arg_t, const Alloc& alloc, F f);

    ~function();

    function& operator=(const function& other);
    function& operator=(function&& other);
    function& operator=(std::nullptr_t);

    template<class F >
    function& operator=(F&& f);

    template<class F >
    function& operator=(std::reference_wrapper<F> f);

    void swap(function& other);

    template<class F, class Alloc >
    void assign(F&& f, const Alloc& alloc);

    explicit operator bool() const;

    R operator()(ArgTypes... args) const;

    const std::type_info& target_type() const;

    template<class T >
    T* target();

    template<class T >
    const T* target() const;
};

template<class R, class... Args>
void swap(function<R(Args...)>& lhs, function<R(Args...)>& rhs);

template<class R, class... ArgTypes >
bool operator==(const std::function<R(ArgTypes...)>& f, std::nullptr_t);

template<class R, class... ArgTypes >
bool operator==(std::nullptr_t, const std::function<R(ArgTypes...)>& f);

template<class R, class... ArgTypes >
bool operator!=(const std::function<R(ArgTypes...)>& f, std::nullptr_t);

template<class R, class... ArgTypes >
bool operator!=(std::nullptr_t, const std::function<R(ArgTypes...)>& f);

class bad_function_call : public std::exception {
public:
    bad_function_call();
};

// SIMPLIFIED: actual result is unspecified, std::function<R> is only for
// providing return type
template<class R, class T >
std::function<R> mem_fn(R T::* pm);

template<class F, class... Args >
std::function<R> bind(F&& f, Args&& ... args);

template<class R, class F, class... Args >
std::function<R> bind(F&& f, Args&& ... args);

#if CPPREFERENCE_STDVER >= 2017
template<class F, class... ArgTypes>
std::result_of_t < F&& (ArgTypes&& ...) > invoke(F&& f, ArgTypes&& ... args);
#endif

// SIMPLIFIED: the inherited type is simplified
template<class T >
struct is_bind_expression : std::integral_constant<bool, true> {};

template<class T >
struct is_placeholder : std::integral_constant<bool, true> {};

namespace placeholders { // SIMPLIFIED: the actual type is unspecified
extern int _1;
extern int _2;
extern int _3;
extern int _4;
extern int _5;
extern int _6;
extern int _7;
extern int _8;
extern int _9;
} // namespace placeholders

template<class T>
class reference_wrapper {
public:
    typedef T type;
    // SIMPLIFIED: actual types are dependent on T
    typedef void result_type;
    typedef void argument_type;
    typedef void first_argument_type;
    typedef void second_argument_type;

    reference_wrapper(T& x);
    reference_wrapper(T&& x) = delete;
    reference_wrapper(const reference_wrapper<T>& other);

    reference_wrapper& operator=(const reference_wrapper<T>& other);

    operator T& () const;
    T& get() const;

    template<class... ArgTypes >
    typename std::result_of < T& (ArgTypes&& ...) >::type
    operator()(ArgTypes&& ... args) const;   // only if T is function
};

template<class T >
std::reference_wrapper<T> ref(T& t);

template<class T >
std::reference_wrapper<T> ref(std::reference_wrapper<T> t);

template <class T>
void ref(const T&&) = delete;

template<class T >
std::reference_wrapper<const T> cref(const T& t);

template<class T >
std::reference_wrapper<const T> cref(std::reference_wrapper<T> t);

template <class T>
void cref(const T&&) = delete;

#endif // CPPREFERENCE_STDVER >= 2011

template<class T = void>
struct plus {
    typedef T result_type;
    typedef T first_argument_type;
    typedef T second_argument_type;
    T operator()(const T& lhs, const T& rhs) const;
};

template<class T = void>
struct minus {
    typedef T result_type;
    typedef T first_argument_type;
    typedef T second_argument_type;
    T operator()(const T& lhs, const T& rhs) const;
};

template<class T = void>
struct multiplies {
    typedef T result_type;
    typedef T first_argument_type;
    typedef T second_argument_type;
    T operator()(const T& lhs, const T& rhs) const;
};

template<class T = void>
struct divides {
    typedef T result_type;
    typedef T first_argument_type;
    typedef T second_argument_type;
    T operator()(const T& lhs, const T& rhs) const;
};

template<class T = void>
struct modulus {
    typedef T result_type;
    typedef T first_argument_type;
    typedef T second_argument_type;
    T operator()(const T& lhs, const T& rhs) const;
};

template<class T = void>
struct negate {
    typedef T result_type;
    typedef T argument_type;
    T operator()(const T& arg) const;
};

template<class T = void>
struct equal_to {
    typedef bool result_type;
    typedef T first_argument_type;
    typedef T second_argument_type;
    bool operator()(const T& lhs, const T& rhs) const;
};

template<class T = void>
struct not_equal_to {
    typedef bool result_type;
    typedef T first_argument_type;
    typedef T second_argument_type;
    bool operator()(const T& lhs, const T& rhs) const;
};

template<class T = void>
struct greater {
    typedef bool result_type;
    typedef T first_argument_type;
    typedef T second_argument_type;
    bool operator()(const T& lhs, const T& rhs) const;
};

template<class T = void>
struct less {
    typedef bool result_type;
    typedef T first_argument_type;
    typedef T second_argument_type;
    bool operator()(const T& lhs, const T& rhs) const;
};

template<class T = void>
struct greater_equal {
    typedef bool result_type;
    typedef T first_argument_type;
    typedef T second_argument_type;
    bool operator()(const T& lhs, const T& rhs) const;
};

template<class T = void>
struct less_equal {
    typedef bool result_type;
    typedef T first_argument_type;
    typedef T second_argument_type;
    bool operator()(const T& lhs, const T& rhs) const;
};

template<class T = void>
struct logical_and {
    typedef bool result_type;
    typedef T first_argument_type;
    typedef T second_argument_type;
    bool operator()(const T& lhs, const T& rhs) const;
};

template<class T = void>
struct logical_or {
    typedef bool result_type;
    typedef T first_argument_type;
    typedef T second_argument_type;
    bool operator()(const T& lhs, const T& rhs) const;
};

template<class T = void>
struct logical_not {
    typedef bool result_type;
    typedef T argument_type;
    bool operator()(const T& arg) const;
};

template<class T = void>
struct bit_and {
    typedef T result_type;
    typedef T first_argument_type;
    typedef T second_argument_type;
    T operator()(const T& lhs, const T& rhs) const;
};

template<class T = void>
struct bit_or {
    typedef T result_type;
    typedef T first_argument_type;
    typedef T second_argument_type;
    T operator()(const T& lhs, const T& rhs) const;
};

template<class T = void>
struct bit_xor {
    typedef T result_type;
    typedef T first_argument_type;
    typedef T second_argument_type;
    T operator()(const T& lhs, const T& rhs) const;
};

template<class T = void>
struct bit_not {
    typedef T result_type;
    typedef T argument_type;
    T operator()(const T& arg) const;
};

template<class Predicate >
struct unary_negate {
    typedef bool result_type;
    typedef typename Predicate::argument_type argument_type;

    explicit unary_negate(const Predicate& pred);
    result_type operator()(argument_type const& x) const;
};

template<class Predicate >
struct binary_negate {
    typedef bool result_type;
    typedef typename Predicate::first_argument_type first_argument_type;
    typedef typename Predicate::second_argument_type second_argument_type;

    explicit binary_negate(const Predicate& pred);
    result_type operator()(const T& lhs, const T& rhs) const;
};

template<class Predicate >
std::unary_negate<Predicate> not1(const Predicate& pred);

template<class Predicate >
std::binary_negate<Predicate> not2(const Predicate& pred);

#if CPPREFERENCE_STDVER >= 2011
template<class Key >
struct hash {
    typedef Key argument_type;
    typedef std::size_t result_type;

    std::size_t operator()(const Key& key) const;
};
#endif
} // namespace std

#endif // CPPREFERENCE_FUNCTIONAL_H