:: *在C ++中是什么意思? [英] What does ::* mean in C++?

问题描述

是什么

 private:
    BOOL (LASreader::*read_simple)();

是平均值吗?

来自LAStools，位于 lasreader.hpp

It's from LAStools, in lasreader.hpp

BOOL 是 typedef bool (来自

BOOL is a typedef bool (from mydefs.hpp), but I don't know what this line is declaring, specifically the ::* (double colon asterisk), and that it looks like a function call.

推荐答案

这是指向成员函数的指针.具体来说， read_simple 是指向 LASreader 类的成员函数的指针，该成员函数接受零参数并返回 BOOL .

It's a pointer to member function. Specifically, read_simple is a pointer to a member function of class LASreader that takes zero arguments and returns a BOOL.

来自cppreference中的示例:

From the example in the cppreference:

struct C {
    void f(int n) { std::cout << n << '\n'; }
};
int main()
{
    void (C::*p)(int) = &C::f; // p points at member f of class C
    C c;
    (c.*p)(1); // prints 1
    C* cptr = &c;
    (cptr->*p)(2); // prints 2
}

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