C：数组结构中的结构数组

Question

I have these structures:

struct menu_item{
    int id;
    char *text;
};

struct menu_tab{
    char *label;
    unsigned char item_count;
    struct menu_item *items;
};

struct menu_page{
    char *label;
    unsigned char tab_count;
    struct menu_tab *tabs;
};

struct Tmenu{
    unsigned char page_count;
    struct menu_page *pages;
};

And I would like to define the whole menu-system:

struct Tmenu menu_test = {
    2,
    {
        "F1",
        2,
        {
            {
                "File",
                8,
                {
                    {1, "text  1"},
                    {2, "text2"},
                    {3, "text3333333"},
                    {4, "text4"},
                    {5, "Hello"},
                    {6, "42"},
                    {7, "world"},
                    {8, "!!!!!!!!"}
                }

            },
            {
                "File2",
                3,
                {
                    {11, "file2 text  1"},
                    {12, "blah"},
                    {13, "..."}
                }

            }
        }
    },
    {
        "F2",
        1,
        {
            {
                "File3",
                5,
                {
                    {151, "The Answer To Life"},
                    {152, "The Universe"},
                    {153, "and everything"},
                    {154, "iiiiiiiiiiiiiiiis"},
                    {42, "Fourty-Two"}
                }

            }
        }
    }
};

But when I try to compile, I get extra brace group at end of initializer error messages.

I tried many different ways to do it, but none of them succeeded. So is it possible at all to use complex structures in C, like this?

Answer 1

不，这种用法是不可能的，至少在“旧”（C89）C中是不可能的。不能使用结构文字来初始化指向所讨论结构的指针 ，因为这不能解决结构在内存中的位置的问题位于。

Answer 2

struct Tmenu menu_test = {
    2,
    {
        "F1",
        2,
        {DATAFILE...},
        {DATAFILE2...}
    },

Should be

struct Tmenu menu_test = {
    2,
    {
        "F1",
        2,
        {
        {DATAFILE...},
        {DATAFILE2...}
        }
    },

because the array of struct will loose the declaration for single braces.

Answer 3

the problem is that you declared a pointer to a struct, but in fact you want an array of structs. Most of time struct name* and struct name[] will be "interchangeable" ( Read K&R to see that they are not the same thing), but in case of static initialization it must be declared as an array so the compiler can expected it to be of fixed size and therefore it can determine the amount of memory to be used for the struct.

I need to improve my answer,but my main point here is that I would not expect something like int a* = {3,3,4,5}; to compile. First the type is different on both sides of the assignment. Second how can the compiler know it is an initialization list for an array and not an struct? Third, how can it know that it should expect 4 elements and not 5?