Retiring crypt(tedunangst.com)

    /* returns ptr. to internal static storage */
    const char *type_to_str(const Type *type);

    /* Explicit buffer argument */
    char msg_buf1[256], msg_buf2[256], msg_buf3[256], ..., msg_buf16[256];
    char *type_to_str(char *buf_to_use, size_t buf_size, const Type *type)

    #include <stdio.h>
    
    struct foo {
        int      bar;   
    };  
    
    #define FOO_TO_STR_SIZE 256
    
    #define foo_to_str(foo) \
        foo_to_str_((char [FOO_TO_STR_SIZE]){ 0 }, FOO_TO_STR_SIZE, (foo))

    /* Implementation detail */  
    __attribute__((nonnull))
    static char *foo_to_str_(char *buf_to_use, size_t size,
        const struct foo *foo)
    {   
        (void)snprintf(buf_to_use, size, "%d", foo->bar);
    
        return buf_to_use;
    }
    
    int main(void)
    {
        const struct foo foo = {
            .bar = 42
        },               foo2 = {
            .bar = 43
        };
        printf("%s %s\n", foo_to_str(&foo),
            foo_to_str(&foo2));
    
        return 0;
    }