Pointers to member functions are very strange animals Answer to exercise: Pointer to member function cast Member Function Pointers and the Fastest Possible C++ Delegates 更新(4/12/2012):研究了下FastDelegates的代码,针对VC,好像我的理解还是有点偏差。
在看APUE Figure1.10的时候发现signal(SIGINT, sig_int)这里的sig_int直接用的函数名,但是看Thinking-in-C++ Vol.2的时候发现mem_fun(&Shape::draw)却对函数名进行了取地址操作,感觉有疑问就查了一下资料,下面的代码可以展示出这两者之间的一些区别 参考资料: http://stackoverflow.com/questions/3050805/pointer...
成员函数指针 我们可以通过 RetType (T::*)(Args…) 匹配这类指针,可以使用 is_member_function_pointer 这个 trait 来判断,通常通过它可以 invoke 对应的方法,如果有 T* t,则可以 (t->*func_ptr)(Args…) 完成调用,语法看起来有点诡异。 奇怪的模板方法调用 有某些时候你得把调用写成 t->template foo<T...
Output 复制 is_member_pointer<trivial *> == false is_member_pointer<int trivial::*> == true is_member_pointer<int (functional::*)()> == true 要求 标头:<type_traits> 命名空间: std 另请参阅 <type_traits> is_member_function_pointer 类 is_member_object_pointer 类 is_pointer 类反馈...
C++: member function pointer for SomeClass,#include<stdio.h>classSomeClass{public:voidsome_member_func(intx,char*p){printf("InSomeClass");};};classDerivedClass:publicSomeC
Functionoids是基于steroids的函数。严格来说比函数功能更强大,而其额外的功能解决了使用函数指针时所面临的一些(不是全部)的挑战。让我们举一个例子说明传统函数指针的使用,然后我们将其转化为使用functionoids的例子。传统的函数指针的思想是定义一堆兼容的函数:The traditional function-pointer idea is to have a ...
C++ Pointer to Member Function A challenge for every C++ programmer are pointer to member functions (ptmf).ptmfs are diffent than their C counterparts - function pointers (fp). Using function pointers in C is a common practice and gives the programmer a powerful technique for a good pice of...
To answer your question why this works: just like the array-to-pointer decay there is a function-to-pointer decay (inherited from C), but it doesn't include member-function-to-pointer decay. You have to take their address explicitly (so your question really should have been: why does it...
base1.print();// Output: Base Function Access Shadowed Function in C++ To access the shadowed function of the base class, we use the scope resolution operator::. We can also access the shadowed function by using apointerof the base class to point to an object of the derived class and ...
error C2662: 'int Something::getValue(void)': cannot convert 'this' pointer from 'const Something' to 'Something &' error: passing 'const Something' as 'this' argument discards qualifiers [-fpermissive] When we call a non-const member function on a const object, the implicit this functio...