我从未见过的std :: vector的新语法.帮助? [英] new syntax for std::vector i've never seen before. help?

问题描述

我刚刚阅读了一些各种文档和论坛，而不是有趣的做事方式，而且我偶然发现了一种我从未见过的语法.有人可以告诉我这是什么意思吗?

i''ve just been reading some various documentation and forums and what not for interesting ways of doing things, and i''ve stumbled upon a syntax i''ve straight up never seen before. can someone tell me what the heck this means?

std::vector <base *(*)()>  vectorArray;

我在很多程序中都使用过向量，但是我以前从未见过这样的事情.显然，它允许您在其中存储函数调用，然后根据该函数调用所在的任何迭代器，您可以进行以下操作:

i''ve been using vectors in many of my programs, but i''ve never seen something like this done before. apparently it allows you store a function call in it, and then, based on whatever iterator that function call is at, you just go:

vectorArray[0] ();

它会调用您放置在其中的任何函数.这似乎是一种为各种派生类调用构造函数的绝妙方法，因此您可以使迭代器与某个类同义，甚至使用map映射:P，但可以使用它为派生类调用构造函数并将其存储为指向基类的指针，但是语法对我来说太陌生了，我想知道是否可以安全使用它.我真的很想:P所以，总而言之，我的问题是，这是做什么的，它是如何做的，此操作是特定于矢量的还是c和c ++数组的常规操作，使用它是否安全? ?

and it calls whatever function you put there. This seems like an excellent way to call constructors for various derived classes, so you can just make an iterator synonymous with a certain class, shoot use a map even :P, but use it to call the constructor for a derived class and store it an a pointer to the base class, but the syntax is so foreign to me, i''m tentative as to whether it''s safe to use it or not. i''d really like to :P so, in summary, my question is, what is this doing, how is it doing it, is this operation specific to vectors or general to c and c++ arrays, and is it safe to use it?

推荐答案

base *(*)()-指向返回"base *"类型的函数的指针.因此，vectorArray可以将base * Fun()类型的函数作为元素.

base *(*)() - pointer to a function which returns a type ''base*''. So, vectorArray can take functions of type base* Fun() as its elements.

base *(*)()

是指向函数的指针的语法，该函数返回指向base的指针；因此您的向量将包含指向函数的指针.

is the syntax for a pointer to a function which returns a pointer to base; so your vector will contain pointers to functions.

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