C++ Class 内部结构动态分配在它的方法

Question

我在 class 中分配 (::operator new) 声明的结构时遇到了一些麻烦，在它的方法中，出现了一个不可读的错误：

error: cannot convert 'Automata::state*' to 'state*' in assignment

\ 我试过删除 "Automata::" 声明，放置 "this->" 和其他随机的东西，但没有成功。遵循示例代码；

#include <iostream>
#include <new>

class Automata{
    public:
        struct quintuple{
            struct state *stateStr = NULL;
            int stateSize = 0;
        };
        struct state{
            struct symbol *symbolStr = NULL;
        };
        struct symbol{
            char *state = NULL;
            int stateSize = 0;
        };
        struct quintuple quintupleStr;
        //Functions
        void quintuple(int stateValidCounter);
};

void Automata::quintuple(int stateValidCounter){
    this->quintupleStr.stateStr = (struct Automata::state *) ::operator new(sizeof(struct Automata::state) * stateValidCounter);
    return;
}

int main(){
    Automata automata; 
    automata.quintuple(5);
    return 0;
}

/*
g++ -std=c++11 example.cpp -o example.out

example.cpp: In member function 'void Automata::quintuple(int)':
example.cpp:23:30: error: cannot convert 'Automata::state*' to 'state*' in assignment
  this->quintupleStr.stateStr = (struct Automata::state *) ::operator new(sizeof(struct Automata::state) * stateValidCounter);
                              ^
*/

感谢关注

Answer 1

嗯，老实说这是一个悲伤的疲劳事件。如果他回答，我愿意接受@Passer By。

答案很简单@Passer 在主要部分发表评论。

成为代码

#include <iostream>
#include <new>

class Automata{
    public:
        struct quintuple{
            struct state *stateStr = NULL;
            int stateSize = 0;
        };
        struct state{....};
        struct quintuple quintupleStr;
        //Functions
        void quintuple(int stateValidCounter);
};

void Automata::quintuple(int stateValidCounter){
    this->quintupleStr.stateStr = (struct Automata::state *) ::operator new(sizeof(struct Automata::state) * stateValidCounter);
    return;
}

int main(){
    Automata automata; 
    automata.quintuple(5);
    return 0;
}

只需切换结构代码位置..

class Automata{
    public:
        struct state{....};
        struct quintuple{
            struct state *stateStr = NULL;
            int stateSize = 0;
        };
        struct quintuple quintupleStr;
        ....;
};

我仍然认为编译器错误有点误导

C++ Class 内部结构动态分配在它的方法

C++ Class internal struct dynamic allocation at its method

c++

struct

class

dynamic-allocation