std::function

 

C++

语言

概念

实用工具库

字符串库

集装箱库

算法库

迭代器库

Numerics库

输入/输出库

本地化库

正则表达式库 （C++11）

原子操作库 （C++11）

线程的支持库 （C++11）

 

实用工具库

类型的支持 (basic types, RTTI, type traits)

动态内存管理

错误处理

程序实用工具

可变参数函数

日期和时间

函数对象

initializer_list （C++11）

bitset

hash （C++11）

关系运算符 Original: Relational operators The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

rel_ops::operator!= rel_ops::operator> rel_ops::operator<= rel_ops::operator>=

双和元组 Original: Pairs and tuples The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

pair

tuple （C++11）

piecewise_construct_t （C++11）

piecewise_construct （C++11）

掉期，远期和移动 Original: Swap, forward and move The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

swap

forward （C++11）

move （C++11）

move_if_noexcept （C++11）

declval （C++11）

 

函数对象

功能包装 Original: Function wrappers The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
function （C++11）
mem_fn （C++11）
bad_function_call （C++11）
绑定 Original: Bind The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
bind （C++11）
is_bind_expression （C++11）
is_placeholder （C++11）
_1, _2, _3, ... （C++11）
参考包装 Original: Reference wrappers The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
reference_wrapper （C++11）
ref cref （C++11） （C++11）
操作包装 Original: Operator wrappers The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
plus minus negate multiplies divides modulus logical_and logical_or logical_not	equal_to not_equal_to greater less greater_equal less_equal bit_and bit_or bit_xor
否定词 Original: Negators The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
unary_negate binary_negate	not1 not2
已过时粘合剂和适配器 Original: Deprecated binders and adaptors The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
unary_function （过时了）
binary_function （过时了）
ptr_fun （过时了）
pointer_to_unary_function （过时了）
pointer_to_binary_function （过时了）
mem_fun （过时了）
mem_fun_t mem_fun1_t const_mem_fun_t const_mem_fun1_t （过时了） （过时了） （过时了） （过时了）
mem_fun_ref （过时了）
mem_fun_ref_t mem_fun1_ref_t const_mem_fun_ref_t const_mem_fun1_ref_t （过时了） （过时了） （过时了） （过时了）
binder1st binder2nd （过时了） （过时了）
bind1st bind2nd （过时了） （过时了）

 

std::function

成员函数 Original: Member functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

function::function

function::~function

function::operator=

function::swap

function::assign

function::operator bool

function::operator()

function::target_type

function::target

非成员函数 Original: Non-member functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

operator== operator!=

std::swap(std::function)

Helper类 Original: Helper classes The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

std::uses_allocator<std::function>

 

Defined in header <functional>
template< class > class function; /* undefined */		（C++11 起）
template< class R, class... Args > class function<R(Args...)>		（C++11 起）

std::function类模板是一个通用的多态函数的包装。 std::function的实例存储，复制，和调用任何可调用的“目标” - 的功能，lambda表达式，绑定表达式，或其他的函数对象.

Original:

Class template std::function is a general-purpose polymorphic function wrapper. Instances of std::function can store, copy, and invoke any callable target -- functions, lambda表达式, 绑定表达式, or other function objects.

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

会员类型

类型 Original: Type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.	Definition
result_type	R
argument_type	T如果sizeof...(Args)==1T在Args...是第一个也是唯一的类型 Original: T if sizeof...(Args)==1 and T is the first and only type in Args... The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
first_argument_type	T1如果sizeof...(Args)==2和T1Args...中的两种类型是第一个 Original: T1 if sizeof...(Args)==2 and T1 is the first of the two types in Args... The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
second_argument_type	T2如果sizeof...(Args)==2和T2Args...中的两种类型的第二个 Original: T2 if sizeof...(Args)==2 and T2 is the second of the two types in Args... The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

成员函数

(constructor)	std::function构造一个新的实例 Original: constructs a new std::function instance The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
(destructor)	销毁一个std::function实例 Original: destroys a std::function instance The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
operator=	分配的内容 Original: assigns the contents The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
swap	交换的内容 Original: swaps the contents The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
assign	分配一个新的目标 Original: assigns a new target The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
operator bool	检查，如果包含一个有效的目标 Original: checks if a valid target is contained The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
operator()	调用的目标 Original: invokes the target The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
目标访问 Original: Target access The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
target_type	获得所存储的目标的typeidstd::function Original: obtains the typeid of the stored target of a std::function The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
target	获得一个指针std::function存储的目标的 Original: obtains a pointer to the stored target of a std::function The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）

非成员函数

std::swap(std::function) （C++11）	专业的std::swap算法 Original: specializes the std::swap algorithm The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （函数模板）
operator== operator!=	比较std::functionstd::nullptr Original: compares an std::function with std::nullptr The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （函数模板）

Helper类

std::uses_allocator<std::function> （C++11）	专业的std::uses_allocator型特征 Original: specializes the std::uses_allocator type trait The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （类模板专业化）

为例

#include <functional>
#include <iostream>
 
struct Foo {
    Foo(int num) : num_(num) {}
    void print_add(int i) const { std::cout << num_+i << '\n'; }
    int num_;
};
 
void print_num(int i)
{
    std::cout << i << '\n';
}
 
int main()
{
    // store a free function
    std::function<void(int)> f_display = print_num;
    f_display(-9);
 
    // store a lambda
    std::function<void()> f_display_42 = []() { print_num(42); };
    f_display_42();
 
    // store the result of a call to std::bind
    std::function<void()> f_display_31337 = std::bind(print_num, 31337);
    f_display_31337();
 
    // store a call to a member function
    std::function<void(const Foo&, int)> f_add_display = &Foo::print_add;
    Foo foo(314159);
    f_add_display(foo, 1);
}

Output:

-9
42
31337
314160

另请参阅

bad_function_call （C++11）	调用一个空的std::function时抛出的异常 Original: the exception thrown when invoking an empty std::function The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （类）
mem_fn （C++11）	创建一个函数对象的指针的成员 Original: creates a function object out of a pointer to a member The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （函数模板）