小编Dam*_*ola的帖子

我有两个文件:main.cpp并crypto.h包含模板类Crypto.在类构造函数中,我需要传递一个函数指针并将其分配给(*keyGen)方法.我需要传递的函数有一个可选的参数

template <class keyType>
class Crypto {
    private:
        keyType (*keyGen)(keyType);

    public:
        Crypto(keyType (*keyGen)(keyType)) {
            this->keyGen = keyGen;
        }

        void decode() {
            keyType foundKey;

            vector<string> output;
            keyType curKey = keyGen(); // Here keyGen has no args

            // if curKey does not decode the input
                curKey = keyGen(curKey); // Here keyGen has 1 arg of type keyType
            // else foundKey = curKey;

            // Save the decoded file
        }
};

在main.cpp中

int keyGen(int key = -1) { // This …