[問題] 成員函數指標一問
開發平台(Platform): (Ex: VC++, GCC, Linux, ...)
Linux GCC
預期的正確結果(Expected Output)：
透過呼叫computing, 投入運算對應的指標函數
並由此函數得到運算結果.
錯誤結果(Wrong Output)：
MathMachine.cpp: In function ‘int main()’:
MathMachine.cpp:27:46: error: no matching function for call to ‘
MathMachine::computing(int, int, int (MathMachine::*&)(int, int))’
MathMachine.cpp:18:5: note: candidate is: int MathMachine::computing(int,
int, int (*)(int, int))
程式碼(Code)：(請善用置底文網頁, 記得排版)
[ MathMachine.h ]
using namespace std;
class MathMachine {
public:
MathMachine();
int add(int, int);
int sub(int, int);
int mul(int, int);
int computing(int , int, int (*) (int, int));
};
[ MathMachine.cpp ]
#include <iostream>
#include "MathMachine.h"
using namespace std;
int MathMachine::add(int x, int y){
return x+y;
}
int MathMachine::sub(int x, int y){
return x-y;
}
int MathMachine::mul(int x, int y){
return x*y;
}
int MathMachine::computing(int x, int y, int (*ptr)(int, int)){
return (*ptr)(x, y);
}
int main(){
MathMachine math;
int (MathMachine::*ptr)(int, int)=0;
ptr = &MathMachine::add;
int result = math.computing(1, 2, ptr);
cout << "the result is : " << result << endl;
return 0;
}
補充說明(Supplement)：
有人跟我說用__thiscall 但gcc下好像沒這東西@@?
請問這該如何改才對呢？
謝謝!!
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