(2)template <classRet,classFn,class... Args>/*unspecified*/bind (Fn&& fn, Args&&... args); bind返回一个基于fn的函数对象(function object), 其参数被绑定到args上. fn的参数要么是绑定到值,要么是绑定到placeholders(占位符,如_1, _2, …, _N) 参数:
Callable object (function object, pointer to function, reference to function, pointer to member function, or pointer to data member) that will be bound to some arguments args - 要绑定的参数列表,未绑定参数为命名空间 std::placeholders 的占位符 _1, _2, _3... 所替换 注解 如可调用 (Callable...
根据cppreference对第二种情况的描述: • If the stored argumentargis of typeTfor which std::is_bind_expression ::value == true (for example, anotherbindexpression was passed directly into the initial call tobind), thenbindperforms function composition: instead of passing the function object that...
#include <functional> #include <iostream> void f(int& n1, int& n2, const int& n3) { std::cout << "In function: " << n1 << ' ' << n2 << ' ' << n3 << '\n'; ++n1; // increments the copy of n1 stored in the function object ++n2; // increments the main()'s n2 ...
Case 1: reference wrappers Ifarg_iis of typestd::reference_wrapper<T>(for example,std::reforstd::crefwas used in the initial call tostd::bind), thenv_iisarg_i.get()and its typeV_iisT&: the stored argument is passed by reference into the invoked function object. ...
::cout << bound_member_data() << '\n'; // 10 return 0; } By default, bind makes a copy of the provided function object. boost::ref and boost::cref can be used to make it store a reference to the function object, rather than a copy. This can be useful when the function ...
std::function<void(const std::string &)> update_; private: void Update(const std::string...
cref 则是const reference void f(int& n1, int& n2, const int& n3) { std::cout << "In function: " << n1 << ' ' << n2 << ' ' << n3 << '\n'; ++n1; // increments the copy of n1 stored in the function object
std::function<void(conststd::vector<Touch*>&, Event*)> onTouchesBegan; AI代码助手复制代码 因为CC_CALLBACK系列是std::bind,而onTouchesBegan是std::function来定义的。那么std::bind和std::function又有什么区别呢? 有博文说: function模板类和bind模板函数,使用它们可以实现类似函数指针的功能,但却比函数指...
1 std::function<void(const std::vector<Touch*>&, Event*)> onTouchesBegan; 因为CC_CALLBACK系列是std::bind,而onTouchesBegan是std::function来定义的。那么std::bind和std::function又有什么区别呢? 有博文说: function模板类和bind模板函数,使用它们可以实现类似函数指针的功能,但却比函数指针更加灵活,特别...