使用本身就是结构的成员进行结构

Question

I have a struct with several members and one of them is the same struct itself. What I want to do is have a pointer to a struct related to that same struct but is of the same type. The compiler does not recognize the type when reading the struct members since it is still to be defined. Is there any alternative way to do what I want to happen?

typedef struct _panels
{
    int id;
    // Dimensions
    double length;
    double height;

    // Global coordinates of origin of LCS
    double origX;
    double origY;
    double origZ;

    // Orientation of local x-axis wrt global X-axis
    double angle;

    // Panel reinforcement
    int nReinforcement;
    double *xReinf; // arbitrary spacing
    double sx;  // fixed spacing
    double xReinf0; // x-coordinate of first rebar

    // CHB unit
    CHBUnit *chb;

    // Openings
    int nOpenings;
    CHBOpening *openings;

    // Pointer to adjacent panels
    CHBPanel * left;    int leftPanelID;
    CHBPanel * right;   int rightPanelID;
}CHBPanel;

Answer 1

You should use the defined (incomplete in the definition of the structure) type struct _panels instead of CHBPanel , which is not defined yet, to declare pointers to the structure itself.

The last part

    CHBPanel * left;    int leftPanelID;
    CHBPanel * right;   int rightPanelID;

should be

    struct _panels * left;    int leftPanelID;
    struct _panels * right;   int rightPanelID;

Alternative way: You can do the typedef before the declaration of the structure.

typedef struct _panels CHBPanel;
struct _panels
{
    int id;

    /* snipped */

    // Pointer to adjacent panels
    CHBPanel * left;    int leftPanelID;
    CHBPanel * right;   int rightPanelID;
};