Question

在我的C ++类中，我有两个静态方法，称为getInstance。

方法声明如下：

public: // +++ STATIC +++
    static CanCommunicator* getInstance(shared_ptr<ThreadState> state);
    static CanCommunicator* getInstance();

在全局函数中（由于遗留代码而需要），我正在从对象中调用吸气剂：

auto tState = CanCommunicator::getInstance()->getThreadState();

编译器（GCC 4.4.5）给我以下错误：

CanCommunicator::getInstance is ambiguous
Candidates are:
CanCommunicator * getInstance()
CanCommunicator * getInstance(std::shared_ptr<IsoTpThreadState>)

是什么原因导致此错误，我该如何解决？实例创建需要重载的方法，无参数的方法用于纯实例检索。

编辑：根据要求提供更多示例代码。

#include <memory>
#include <stdint.h>
#include <linux/can.h>
#include <linux/can/raw.h>

using std::shared_ptr;

//================
// Class in question
//================

struct ThreadState {
    int32_t socketFd;
    uint32_t sendId;
};

class CanCommunicator {
    #define null NULL

    public: // +++ STATIC +++
        static CanCommunicator* getInstance(shared_ptr<ThreadState> state);
        static CanCommunicator* getInstance();
    public:
        shared_ptr<ThreadState> getThreadState() { return this->threadState; }
    protected:
        CanCommunicator(shared_ptr<ThreadState> state);
    private: // +++ STATIC +++
        static CanCommunicator* instance;
    private:
        shared_ptr<ThreadState> threadState;
};


/*
 +++++++++++++++++++++++++++++++++++++
 +++       STATIC VARIABLES        +++
 +++++++++++++++++++++++++++++++++++++
 */

CanCommunicator* CanCommunicator::instance = null;


/*
 +++++++++++++++++++++++++++++++++++++
 +++        STATIC METHODS         +++
 +++++++++++++++++++++++++++++++++++++
 */

CanCommunicator* CanCommunicator::getInstance(shared_ptr<ThreadState> state) {
    if (state == null && instance == null)
        throw "Cannot instantiate from nullptr!";

    return instance == null ? (instance = new CanCommunicator(state)) : instance;
}

CanCommunicator* CanCommunicator::getInstance() { return instance == null ? throw "No instance found!" : instance; }

CanCommunicator::CanCommunicator(shared_ptr<ThreadState> state) {
    this->threadState = state;        
}

//================
// Calling code
//================

int canSendData(int32_t skt, uint32_t sendCanId, const uint8_t* data, uint8_t dataLength, uint8_t extended) {
    struct can_frame myCanFrame;
    return (int)write(skt, &myCanFrame, sizeof(myCanFrame));
}

int isotp_user_send_can(const uint32_t arbitrationId, const uint8_t* data, const uint8_t size) {
    auto tState = CanCommunicator::getInstance()->getThreadState(); //<-------- Error originates here
    return canSendData(tState->socketFd, (int)tState->sendId, data, size, false) > 0 ? 0 : 1;
}

Answer 1

由于Radoslaw的建议，我只是将有问题的函数重命名为getInstanceByState（）。

这似乎是我使用的GCC（4.4.5）版本中的错误，因此没有真正的解决方法，只能等到我可以使用（很多）较新的编译器版本。

感谢所有提供帮助和建议的人。

调用静态重载（类）函数/方法不明确

1 个答案: