Question

我收到此错误：

In function 'bool detect_feedback(AudioEffect*)':

54:30: error: cannot convert 'std::shared_ptr<AudioEffect>' to 'AudioEffect*' in assignment

55:16: error: cannot convert 'std::shared_ptr<AudioEffect>' to 'AudioEffect*' in assignment

55:40: error: cannot convert 'std::shared_ptr<AudioEffect>' to 'AudioEffect*' in assignment

代码如下：

#include<stdlib.h>
#include<iostream>
#include<memory>`

//BASE CLASS

// audio and have a subsequent effect (next).

struct AudioEffect 
{
    virtual ~AudioEffect() = default;
    virtual void process(float* buf, size_t num) = 0;
    std::shared_ptr<AudioEffect> next;
};

//DERIVING MULTIPLE AUDIO-EFFECTS

//Noise Gate

struct NoiseGate: public AudioEffect
{
    float threshold;
    void process(float *buf, size_t num)
    {
        if (*buf > threshold)
            *buf = threshold;
    }
};

//Gain Boost

struct GainBoost: public AudioEffect
{
    float signal;
    void process(float *buf, size_t num)
    {
        *buf = *buf + signal;
    }
};

//Compressor

struct Compressor: public AudioEffect
{
    float offset;
    void process(float *buf, size_t num)
    {
        *buf = *buf - offset;
    }
};

//Function
// Implement a function that checks if there is a feedback loop
// in the effects chain.
//... detect_feedback(...)
//{
//} 

bool detect_feedback (AudioEffect *ae)
{
    AudioEffect *p, *q;
    for (p = ae;p != NULL; p = p->next)
        for (q = p->next; q != NULL; q = q->next)
            if (typeid(*p) == typeid(*q))
                return true;
    return false;
}

//MAIN

int main(int argc, char *argv[])
{    
    return 0;
}

Answer 1

您无法将shared_ptr分配给原始指针。您需要使用.get()方法获取原始指针。

(p->next).get()

纯虚函数错误

1 个答案: