C++ 在不使用单独的 typedef 的情况下声明函数指针数组的语法是什么?
声明:本页面是StackOverFlow热门问题的中英对照翻译,遵循CC BY-SA 4.0协议,如果您需要使用它,必须同样遵循CC BY-SA许可,注明原文地址和作者信息,同时你必须将它归于原作者(不是我):StackOverFlow
原文地址: http://stackoverflow.com/questions/5093090/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
What's the syntax for declaring an array of function pointers without using a separate typedef?
提问by Maxpm
Arrays of function pointers can be created like so:
可以像这样创建函数指针数组:
typedef void(*FunctionPointer)();
FunctionPointer functionPointers[] = {/* Stuff here */};
What is the syntax for creating a function pointer array without using the typedef
?
在不使用typedef
? 的情况下创建函数指针数组的语法是什么?
回答by Armen Tsirunyan
arr //arr
arr [] //is an array (so index it)
* arr [] //of pointers (so dereference them)
(* arr [])() //to functions taking nothing (so call them with ())
void (* arr [])() //returning void
so your answer is
所以你的答案是
void (* arr [])() = {};
But naturally, this is a bad practice, just use typedefs
:)
但自然,这是一个不好的做法,只需使用typedefs
:)
Extra:Wonder how to declare an array of 3 pointers to functions taking int and returning a pointer to an array of 4 pointers to functions taking double and returning char? (how cool is that, huh? :))
额外:想知道如何声明一个包含 3 个指针的数组,该数组指向采用 int 的函数并返回一个指向 4 个指向采用 double 并返回 char 的函数的指针数组的指针?(这有多酷,嗯?:))
arr //arr
arr [3] //is an array of 3 (index it)
* arr [3] //pointers
(* arr [3])(int) //to functions taking int (call it) and
*(* arr [3])(int) //returning a pointer (dereference it)
(*(* arr [3])(int))[4] //to an array of 4
*(*(* arr [3])(int))[4] //pointers
(*(*(* arr [3])(int))[4])(double) //to functions taking double and
char (*(*(* arr [3])(int))[4])(double) //returning char
:))
:))
回答by Logan Capaldo
Remember "delcaration mimics use". So to use said array you'd say
记住“声明模仿使用”。所以要使用所说的数组,你会说
(*FunctionPointers[0])();
Correct? Therefore to declare it, you use the same:
正确的?因此要声明它,您使用相同的:
void (*FunctionPointers[])() = { ... };
回答by Erik
Use this:
用这个:
void (*FunctionPointers[])() = { };
Works like everything else, you place [] after the name.
像其他一切一样工作,您将 [] 放在名称后面。