Standard library header <functional>

From cppreference.com
< cpp‎ | header
 
C++
 
Standard Library header files
 

This header is part of the function objects library and provides the standard hash function.

Contents

[edit] Namespaces

placeholders Defines placeholders for the unbound arguments in a std::bind expression
Constants
Defined in namespace std::placeholders
(C++11)
 placeholders for the unbound arguments in a std::bind expression
(constant)

[edit] Classes

(C++11)
 wraps callable object of any type with specified function call signature
(class template)
(C++11)
 creates a function object out of a pointer to a member
(function template)
(C++11)
 the exception thrown when invoking an empty std::function
(class)
(C++11)
 indicates that an object is std::bind expression or can be used as one
(class template)
(C++11)
 indicates that an object is a standard placeholder or can be used as one
(class template)
(C++11)
 CopyConstructible and CopyAssignable reference wrapper
(class template)
Hashing
(C++11)
 hash function object
(class template)
template<> struct hash<bool>;

template<> struct hash<char>;
template<> struct hash<signed char>;
template<> struct hash<unsigned char>;
template<> struct hash<char16_t>;
template<> struct hash<char32_t>;
template<> struct hash<wchar_t>;
template<> struct hash<short>;
template<> struct hash<unsigned short>;
template<> struct hash<int>;
template<> struct hash<unsigned int>;
template<> struct hash<long>;
template<> struct hash<long long>;
template<> struct hash<unsigned long>;
template<> struct hash<unsigned long long>;
template<> struct hash<float>;
template<> struct hash<double>;
template<> struct hash<long double>;
template< class T > struct hash<T*>;

 		std::hash specializations for built-in types
(class template specialization)


[edit] Functions

(C++11)
 binds one or more arguments to a function object
(function template)
(C++11)(C++11)
 creates a std::reference_wrapper with a type deduced from its argument
(function template)


[edit] Function Objects

Arithmetic operations
function object implementing x + y
(class template)
function object implementing x - y
(class template)
function object implementing x * y
(class template)
function object implementing x / y
(class template)
function object implementing x % y
(class template)
function object implementing -x
(class template)
Comparisons
function object implementing x == y
(class template)
function object implementing x != y
(class template)
function object implementing x > y
(class template)
function object implementing x < y
(class template)
function object implementing x >= y
(class template)
function object implementing x <= y
(class template)
Logical operations
function object implementing x && y
(class template)
function object implementing x || y
(class template)
function object implementing !x
(class template)
Bitwise operations
function object implementing x & y
(class template)
function object implementing x | y
(class template)
function object implementing x ^ y
(class template)
Negators
wrapper function object returning the complement of the unary predicate it holds
(class template)
wrapper function object returning the complement of the binary predicate it holds
(class template)
constructs custom std::unary_negate object
(function template)
constructs custom std::binary_negate object
(function template)

[edit] Deprecated in C++11

Base
(deprecated)
 adaptor-compatible unary function base class
(class template)
(deprecated)
 adaptor-compatible binary function base class
(class template)
Binders
(deprecated)(deprecated)
 function object holding a binary function and one of its arguments
(class template)
(deprecated)(deprecated)
 binds one argument to a binary function
(function template)
Function adaptors
(deprecated)
 adaptor-compatible wrapper for a pointer to unary function
(class template)
(deprecated)
 adaptor-compatible wrapper for a pointer to binary function
(class template)
(deprecated)
 creates an adaptor-compatible function object wrapper from a pointer to function
(function template)
(deprecated)(deprecated)(deprecated)(deprecated)
 wrapper for a pointer to nullary or unary member function, callable with a pointer to object
(class template)
(deprecated)
 creates a wrapper from a pointer to member function, callable with a pointer to object
(function template)
(deprecated)(deprecated)(deprecated)(deprecated)
 wapper for a pointer to nullary or unary member function, callable with a reference to object
(class template)
(deprecated)
 creates a wrapper from a pointer to member function, callable with a reference to object
(function template)

[edit] Synopsis 

namespace std {
 
    // base (deprecated):
    template <class Arg, class Result> struct unary_function;
    template <class Arg1, class Arg2, class Result> struct binary_function;
 
    // reference_wrapper:
    template <class T> class reference_wrapper;
    template <class T> reference_wrapper<T> ref(T&) noexcept;
    template <class T> reference_wrapper<const T> cref(const T&) noexcept;
    template <class T> void ref(const T&&) = delete;
    template <class T> void cref(const T&&) = delete;
    template <class T> reference_wrapper<T> ref(reference_wrapper<T>) noexcept;
    template <class T> reference_wrapper<const T> cref(reference_wrapper<T>) noexcept;
 
    // arithmetic operations:
    template <class T> struct plus;
    template <class T> struct minus;
    template <class T> struct multiplies;
    template <class T> struct divides;
    template <class T> struct modulus;
    template <class T> struct negate;
 
    // comparisons:
    template <class T> struct equal_to;
    template <class T> struct not_equal_to;
    template <class T> struct greater;
    template <class T> struct less;
    template <class T> struct greater_equal;
    template <class T> struct less_equal;
 
    // logical operations:
    template <class T> struct logical_and;
    template <class T> struct logical_or;
    template <class T> struct logical_not;
 
    // bitwise operations:
    template <class T> struct bit_and;
    template <class T> struct bit_or;
    template <class T> struct bit_xor;
 
    // negators:
    template <class Predicate> class unary_negate;
    template <class Predicate>
        unary_negate<Predicate> 
        not1(const Predicate&);
    template <class Predicate>  class binary_negate;
    template <class Predicate>
        binary_negate<Predicate>
        not2(const Predicate&);
 
    // bind:
    template<class T> struct is_bind_expression;
    template<class T> struct is_placeholder;
    template<class  F, class... BoundArgs>
        /*unspecified*/ bind(F&&, BoundArgs&&...);
    template<class  R, class F, class... BoundArgs>
        /*unspecified*/ bind(F&&, BoundArgs&&...);
 
    namespace placeholders {
        // M is the implementation-defined number of placeholders
        extern /*unspecified*/ _1;
        extern /*unspecified*/ _2;
        .
        .
        .
        extern /*unspecified*/ _M;
    }
 
    // binders (deprecated):
    template <class Fn> class binder1st;
    template <class Fn, class T>
        binder1st<Fn> bind1st(const Fn&, const T&);
    template <class Fn> class binder2nd;
    template <class Fn, class T>
        binder2nd<Fn> bind2nd(const Fn&, const T&);
 
    // adaptors (deprecated):
    template <class Arg, class Result> class pointer_to_unary_function;
    template <class Arg, class Result>
        pointer_to_unary_function<Arg,Result> ptr_fun(Result (*)(Arg));
    template <class Arg1, class Arg2, class Result>
        class pointer_to_binary_function;
    template <class Arg1, class Arg2, class Result>
        pointer_to_binary_function<Arg1,Arg2,Result>
        ptr_fun(Result (*)(Arg1,Arg2));
 
    // adaptors (deprecated):
    template<class S, class T> class mem_fun_t;
    template<class S, class T, class A> class mem_fun1_t;
    template<class S, class T>
        mem_fun_t<S,T> mem_fun(S (T::*f)());
    template<class S, class T, class A>
        mem_fun1_t<S,T,A> mem_fun(S (T::*f)(A));
    template<class S, class T> class mem_fun_ref_t;
    template<class S, class T, class A> class mem_fun1_ref_t;
    template<class S, class T>
        mem_fun_ref_t<S,T> mem_fun_ref(S (T::*f)());
    template<class S, class T, class A>
        mem_fun1_ref_t<S,T,A> mem_fun_ref(S (T::*f)(A));
    template <class S, class T> class const_mem_fun_t;
    template <class S, class T, class A> class const_mem_fun1_t;
    template <class S, class T>
        const_mem_fun_t<S,T> mem_fun(S (T::*f)() const);
    template <class S, class T, class A>
        const_mem_fun1_t<S,T,A> mem_fun(S (T::*f)(A) const);
    template <class S, class T> class const_mem_fun_ref_t;
    template <class S, class T, class A> class const_mem_fun1_ref_t;
    template <class S, class T>
        const_mem_fun_ref_t<S,T> mem_fun_ref(S (T::*f)() const);
    template <class S, class T, class A>
        const_mem_fun1_ref_t<S,T,A> mem_fun_ref(S (T::*f)(A) const);
 
    // member function adaptors:
    template<class R, class T> /*unspecified*/ mem_fn(R T::*);
    template<class R, class T, class... Args>
        /*unspecified*/ mem_fn(R (T::*)(Args...));
    template<class R, class T, class... Args>
        /*unspecified*/ mem_fn(R (T::*)(Args...) const);
    template<class R, class T, class... Args>
        /*unspecified*/ mem_fn(R (T::*)(Args...) volatile);
    template<class R, class T, class... Args>
        /*unspecified*/ mem_fn(R (T::*)(Args...) const volatile);
    template<class R, class T, class... Args>
        /*unspecified*/ mem_fn(R (T::*)(Args...) &);
    template<class R, class T, class... Args>
        /*unspecified*/ mem_fn(R (T::*)(Args...) const &);
    template<class R, class T, class... Args>
        /*unspecified*/ mem_fn(R (T::*)(Args...) volatile &);
    template<class R, class T, class... Args>
        /*unspecified*/ mem_fn(R (T::*)(Args...) const volatile &);
    template<class R, class T, class... Args>
        /*unspecified*/ mem_fn(R (T::*)(Args...) &&);
    template<class R, class T, class... Args>
        /*unspecified*/ mem_fn(R (T::*)(Args...) const &&);
    template<class R, class T, class... Args>
        /*unspecified*/ mem_fn(R (T::*)(Args...) volatile &&);
    template<class R, class T, class... Args>
        /*unspecified*/ mem_fn(R (T::*)(Args...) const volatile &&);
 
    // polymorphic function wrappers:
    class bad_function_call;
    template<class> class function; // undefined
    template<class R, class... ArgTypes> class function<R(ArgTypes...)>;
    template<class R, class... ArgTypes>
        void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&);
    template<class R, class... ArgTypes>
        bool operator==(const function<R(ArgTypes...)>&, nullptr_t);
    template<class R, class... ArgTypes>
        bool operator==(nullptr_t, const function<R(ArgTypes...)>&);
    template<class R, class... ArgTypes>
        bool operator!=(const function<R(ArgTypes...)>&, nullptr_t);
    template<class R, class... ArgTypes>
        bool operator!=(nullptr_t, const function<R(ArgTypes...)>&);
 
    // hash function base template:
    template <class T> struct hash;
 
    // Hash function specializations
    template <> struct hash<bool>;
    template <> struct hash<char>;
    template <> struct hash<signed char>;
    template <> struct hash<unsigned char>;
    template <> struct hash<char16_t>;
    template <> struct hash<char32_t>;
    template <> struct hash<wchar_t>;
    template <> struct hash<short>;
    template <> struct hash<unsigned short>;
    template <> struct hash<int>;
    template <> struct hash<unsigned int>;
    template <> struct hash<long>;
    template <> struct hash<long long>;
    template <> struct hash<unsigned long>;
    template <> struct hash<unsigned long long>;
    template <> struct hash<float>;
    template <> struct hash<double>;
    template <> struct hash<long double>;
    template<class T> struct hash<T*>;
 
}


[edit] Class std::reference_wrapper 

template <class T> class reference_wrapper {
public :
    // types
    typedef T type;
    typedef /*Return type of T*/     result_type;          // not always defined
    typedef /*Single argument of T*/ argument_type;        // not always defined
    typedef /*1st argument of T*/    first_argument_type;  // not always defined
    typedef /*2nd argument of T*/    second_argument_type; // not always defined
 
    // construct/copy/destroy
    reference_wrapper(T&) noexcept;
    reference_wrapper(T&&) = delete;
 
    // do not bind to temporary objects
    reference_wrapper(const reference_wrapper<T>& x) noexcept;
 
    // assignment
    reference_wrapper& operator=(const reference_wrapper<T>& x) noexcept;
 
    // access
    operator T& () const noexcept;
    T& get() const noexcept;
 
    // invocation
    template <class... ArgTypes>
        typename result_of<T&(ArgTypes&&...)>::type
        operator() (ArgTypes&&...) const;
 
};

[edit] Class std::is_bind_expression 

template<class T> struct is_bind_expression
    : integral_constant<bool, /*true


[edit] Class std::bad_function_call 

class bad_function_call : public std::exception {
public:
    // constructor:
    bad_function_call() noexcept;
};

[edit] Class std::function 

template<class> class function; // undefined
 
template<class R, class... ArgTypes>
class function<R(ArgTypes...)> {
public:
    typedef R result_type;      
    typedef T1 argument_type;       //  iff sizeof...(ArgTypes) == 1 and
                                    //  the type in ArgTypes is T1
    typedef T1 first_argument_type; //  iff sizeof...(ArgTypes) == 2 and
                                    //  ArgTypes contains T1 and T2
    typedef T2 second_argument_type;//  iff sizeof...(ArgTypes) == 2 and
                                    //  ArgTypes contains T1 and T2
 
    // construct/copy/destroy:
    function() noexcept;
    function(nullptr_t) noexcept;
    function(const function&);
    function(function&&);
 
    template<class F> function(F);
    template<class A> function(allocator_arg_t, const A&) noexcept;
    template<class A> function(allocator_arg_t, const A&, nullptr_t) noexcept;
    template<class A> function(allocator_arg_t, const A&, const function&);
    template<class A> function(allocator_arg_t, const A&, function&&);
    template<class F, class A> function(allocator_arg_t, const A&, F);
 
    function& operator=(const function&);
    function& operator=(function&&);
    function& operator=(nullptr_t);
    template<class F> function& operator=(F&&);
    template<class F> function& operator=(reference_wrapper<F>) noexcept;
 
    ~function();
 
    // function modifiers:
    void swap(function&) noexcept;
    template<class F, class A> void assign(F&&, const A&);
 
    // function capacity:
    explicit operator bool() const noexcept;
 
    // function invocation:
    R operator()(ArgTypes...) const;
 
    // function target access:
    const std::type_info& target_type() const noexcept;
    template <typename T>       T* target() noexcept;
    template <typename T> const T* target() const noexcept;
 
};


[edit] See Also

<string> Specializes std::hash for std::string, std::u16string, std::u32string, std::wstring
<system_error> Specializes std::hash for std::error_code
<bitset> Specializes std::hash for std::bitset
<memory> Specializes std::hash for std::unique_ptr, std::shared_ptr
<typeindex> Specializes std::hash for std::type_index
<vector> Specializes std::hash for std::vector<bool>
<thread> Specializes std::hash for std::thread::id
Retrieved from "http://en.cppreference.com/mwiki/index.php?title=cpp/header/functional&oldid=57485"