c++ - 结构前向声明错误 : Typedef redefinition with different types

Question

我想在头文件中转发声明一个结构。

struct GLFWvidmode;

class DesktopVideoMode {
private:
    const GLFWvidmode *videomode;
public:
    DesktopVideoMode(const GLFWvidmode *videomode);
...

在 cpp 文件中，我包含了带有定义的外部 header ...

#include "DesktopVideoMode.hpp"
#include <GLFW/glfw3.h>

...发生错误“Typedef redefinition with different types ('struct GLFWvidmode' vs 'GLFWvidmode')”:

typedef struct
{
    /*! The width, in screen coordinates, of the video mode.
     */
    int width;
    /*! The height, in screen coordinates, of the video mode.
     */
    int height;
    /*! The bit depth of the red channel of the video mode.
     */
    int redBits;
    /*! The bit depth of the green channel of the video mode.
     */
    int greenBits;
    /*! The bit depth of the blue channel of the video mode.
     */
    int blueBits;
    /*! The refresh rate, in Hz, of the video mode.
     */
    int refreshRate;
} GLFWvidmode;

我不能在这种情况下转发声明吗？

Answer 1

GLFWvidmode 不是结构，它是 typedef。您不能转发声明 typedef。选择使用未命名结构的人做出了糟糕的设计决定。