C static initializer element is not constant error

Question

this is my source code in C language i want to definition basic data using static, out side the function

#include <stdio.h>

typedef struct {
    char * URI;
    char * file;
} redirect_t;

typedef struct {
    char * URI;
    char * file;
    long long content_length;
} content_t;

typedef struct {
    content_t contents[10];
    redirect_t redirects[10];
} host_t;

typedef struct {
    unsigned max_requests;
    host_t hosts[10];
} addr_t;

static addr_t addr_list[] = {
        (addr_t) { 24,
            {
                (host_t) {
                    {
                        (content_t) { "URI" },
                        (content_t) { "URI2" },
                        (content_t) { "URI3" },
                    },
                    {
                        (redirect_t) { "URI5" },
                        (redirect_t) { "URI6" },
                        (redirect_t) { "URI7" },
                    }
                }
            }
        }
};

int main() {


    return 0;
}

but i got (initializer element is not constant) error

and this is my compile result

C:\Users\x\Documents\C Projects\untitled\main.c:27:26: error: initializer element is not constant
                 (host_t) {
                          ^
C:\Users\x\Documents\C Projects\untitled\main.c:27:26: note: (near initialization for '(anonymous).hosts')
C:\Users\x\Documents\C Projects\untitled\main.c:25:18: error: initializer element is not constant
         (addr_t) { 24,
                  ^
C:\Users\x\Documents\C Projects\untitled\main.c:25:18: note: (near initialization for 'addr_list')
C:\Users\x\Documents\C Projects\untitled\main.c:25:9: error: initializer element is not constant

i know that i can use malloc inside a function and insert the data into the (addr_list) but i want to insert it directly without any dynamic allocation. what is the problem? why i get error like this !

Answer 1

Yes, using compound literals in this way is non-standard, they are not considered "constants" but objects. The right tool are designated initializers. E.g for your type host_t an initializer would look like

                {
                    .contents  = { .URI = "URI",  },
                    .redirects = { .URI = "URI5", },
                },