C++自定义类赋值报no suitable copy constructor及C2679错误求助

两个核心语法问题直接触发编译报错：

• 自定义拷贝构造函数的参数为CTextureBuffer&非const左值引用，无法绑定到CTextureBuffer(image->w, image->h, image->pixels)生成的临时右值对象。
• 赋值运算符采用值传递方式接收参数，传参时需要调用拷贝构造函数构造形参，拷贝构造匹配失败后编译器判定没有符合要求的=运算符，抛出C2679错误。

基础版本（浅拷贝，匹配现有业务逻辑） #

你当前的业务逻辑只需要拷贝纹理参数和指针，不需要复制纹理数据，直接使用编译器默认生成的拷贝逻辑即可，修复后代码如下：

class CTextureBuffer {
public:
    int m_width = 0;
    int m_height = 0;
    void* m_data = nullptr;

    CTextureBuffer(int width = 0, int height = 0, void* data = nullptr) 
        : m_width(width), m_height(height), m_data(data) {}

    // 拷贝构造加const修饰，支持绑定临时右值和const对象
    CTextureBuffer(const CTextureBuffer& other) = default;
    // 赋值运算符返回类引用，符合C++运算符重载规范
    CTextureBuffer& operator=(const CTextureBuffer& other) = default;

    // 可选：添加移动语义实现，提升临时对象赋值的性能
    CTextureBuffer(CTextureBuffer&& other) = default;
    CTextureBuffer& operator=(CTextureBuffer&& other) = default;
};

进阶版本（深拷贝，独立管理纹理资源） #

如果需要让CTextureBuffer持有纹理数据的所有权，不依赖SDL_Surface的生命周期，可以实现深拷贝逻辑：

class CTextureBuffer {
public:
    int m_width = 0;
    int m_height = 0;
    void* m_data = nullptr;
    // 存储每个像素的字节数，根据SDL_Surface的format计算
    int m_pitch = 0;

    CTextureBuffer(int width = 0, int height = 0, void* data = nullptr, int pitch = 4) 
        : m_width(width), m_height(height), m_pitch(pitch) {
        if (data && width > 0 && height > 0) {
            // 分配内存拷贝纹理数据
            m_data = malloc(width * height * pitch);
            memcpy(m_data, data, width * height * pitch);
        }
    }

    CTextureBuffer(const CTextureBuffer& other) {
        m_width = other.m_width;
        m_height = other.m_height;
        m_pitch = other.m_pitch;
        if (other.m_data) {
            m_data = malloc(m_width * m_height * m_pitch);
            memcpy(m_data, other.m_data, m_width * m_height * m_pitch);
        }
    }

    CTextureBuffer& operator=(const CTextureBuffer& other) {
        if (this == &other) return *this;
        // 释放原有内存
        if (m_data) free(m_data);
        m_width = other.m_width;
        m_height = other.m_height;
        m_pitch = other.m_pitch;
        if (other.m_data) {
            m_data = malloc(m_width * m_height * m_pitch);
            memcpy(m_data, other.m_data, m_width * m_height * m_pitch);
        } else {
            m_data = nullptr;
        }
        return *this;
    }

    ~CTextureBuffer() {
        if (m_data) free(m_data);
    }

    // 可选移动语义
    CTextureBuffer(CTextureBuffer&& other) noexcept {
        m_width = other.m_width;
        m_height = other.m_height;
        m_pitch = other.m_pitch;
        m_data = other.m_data;
        other.m_data = nullptr;
        other.m_width = other.m_height = other.m_pitch = 0;
    }

    CTextureBuffer& operator=(CTextureBuffer&& other) noexcept {
        if (this == &other) return *this;
        if (m_data) free(m_data);
        m_width = other.m_width;
        m_height = other.m_height;
        m_pitch = other.m_pitch;
        m_data = other.m_data;
        other.m_data = nullptr;
        other.m_width = other.m_height = other.m_pitch = 0;
        return *this;
    }
};

1. 添加入参前置校验，避免第一个文件名为空的非法输入
2. 补充SDL_Surface资源释放逻辑，避免内存泄漏：如果用浅拷贝版本，需要自行管理所有加载的SDL_Surface生命周期；如果用深拷贝版本，拷贝完纹理数据后即可调用SDL_FreeSurface释放image对象。
   优化后的业务代码示例：

bool CTexture::Load(CArray<CString>& fileNames, bool flipVertically) {
    m_fileNames = fileNames;
    // 前置校验第一个文件名不能为空
    if (fileNames.IsEmpty() || fileNames[0]->IsEmpty()) {
        fprintf(stderr, "First cubemap face filename can not be empty\n");
        return false;
    }
    CTextureBuffer texBuf;
    for (auto const& fileName : fileNames) {
        if (fileName->Length()) {
            SDL_Surface* image = IMG_Load((char*)(*fileName));
            if (!image) {
                fprintf(stderr, "Couldn't find '%s'\n", (char*)(*fileName));
                return false;
            }
            // 深拷贝版本调用：传入pitch参数，注意根据实际SDL_Surface格式调整
            texBuf = CTextureBuffer(image->w, image->h, image->pixels, image->pitch / image->w);
            // 深拷贝版本可直接释放surface
            SDL_FreeSurface(image);
        }
        m_buffers.Append(texBuf);
    }
    return true;
}

内容的提问来源于stack exchange，提问作者Razzupaltuff