sc/queue/README.md

### Generic queue

### Overview

- Type generic queue which grows when you add elements.
- Add/remove from head/tail is possible so it can be used as list, stack,  
  queue, dequeue etc.


### Usage


```c
#include "sc_queue.h"

#include <stdio.h>

int main(int argc, char *argv[])
{
    int *queue;
    int elem;

    sc_queue_create(queue, 0);

    sc_queue_add_last(queue, 2);
    sc_queue_add_last(queue, 3);
    sc_queue_add_last(queue, 4);
    sc_queue_add_first(queue, 1);

    sc_queue_foreach (queue, elem) {
        printf("elem = [%d] \n", elem);
    }

    elem = sc_queue_del_last(queue);
    printf("Last element was : [%d] \n", elem);

    elem = sc_queue_del_first(queue);
    printf("First element was : [%d] \n", elem);

    sc_queue_destroy(queue);

    return 0;
}
```

### Note

Queue pointer is not stable, it may change if it expands the memory. If you  
pass the queue to another function which can add items, do it by passing  
reference of the queue pointer.

```c
void some_function_to_add_elems(long **q)
{
    sc_queue_add_last(*q, 500);
}

int main(int argc, char *argv[])
{
    long *q;

    sc_queue_create(q, 0);
    sc_queue_add_last(q, 300);
    
    some_function_to_add_elems(&q);
    sc_array_destroy(q);
}
```

Most probably you will hold queue pointer in a struct anyway, so you have a  
stable address of the pointer, "*numbers" might change but "numbers" is stable :

```c
struct my_app {
    int *numbers;
};

void func(struct my_app* app)
{
    sc_queue_add_last(app->numbers, 300);
    sc_queue_add_last(app->numbers, 400);
    sc_queue_add_last(app->numbers, 500);
}
```