<!-- ##### SECTION Title ##### -->
Pointer Arrays

<!-- ##### SECTION Short_Description ##### -->
arrays of pointers to any type of data, which grow automatically as new
elements are added.

<!-- ##### SECTION Long_Description ##### -->
<para>
Pointer Arrays are similar to Arrays but are used only for storing pointers.
</para>
<note>
<para>
If you remove elements from the array, elements at the end of the array
are moved into the space previously occupied by the removed element.
This means that you should not rely on the index of particular elements
remaining the same. You should also be careful when deleting elements while
iterating over the array.
</para>
</note>
<para>
To create a pointer array, use g_ptr_array_new().
</para>
<para>
To add elements to a pointer array, use g_ptr_array_add().
</para>
<para>
To remove elements from a pointer array, use g_ptr_array_remove(), and
g_ptr_array_remove_index().
</para>
<para>
To access an element of a pointer array, use g_ptr_array_index().
</para>
<para>
To set the size of a pointer array, use g_ptr_array_set_size().
</para>
<para>
To free a pointer array, use g_ptr_array_free().
</para>
<example>
<title>Using a GPtrArray.</title>
<programlisting>
  GPtrArray *gparray;
  gchar *string1 = "one", *string2 = "two", *string3 = "three";

  gparray = g_ptr_array_new ();
  g_ptr_array_add (gparray, (gpointer) string1);
  g_ptr_array_add (gparray, (gpointer) string2);
  g_ptr_array_add (gparray, (gpointer) string3);

  if (g_ptr_array_index (gparray, 0) != (gpointer) string1)
    g_print ("ERROR: got %p instead of %p\n",
             g_ptr_array_index (gparray, 0), string1);

  g_ptr_array_free (gparray, TRUE);
</programlisting></example>

<!-- ##### STRUCT GPtrArray ##### -->
<para>
Contains the public fields of a pointer array.
The <structfield>pdata</structfield> field points to the array of pointers,
which may as when the array grows.
The <structfield>len</structfield> field is the number of pointers in the
array.
</para>


<!-- ##### FUNCTION g_ptr_array_new ##### -->
<para>
Creates a new #GPtrArray.
</para>

@Returns: the new #GPtrArray.

<!-- ##### FUNCTION g_ptr_array_add ##### -->
<para>
Adds a pointer to the end of the pointer array.
The array will grow in size automatically if necessary.
</para>

@array: a #GPtrArray.
@data: the pointer to add.

<!-- ##### FUNCTION g_ptr_array_remove ##### -->
<para>
Removes the first occurrence of given pointer from the pointer array.
It returns TRUE if the pointer was removed, or FALSE if the pointer
was not found.
</para>
<note>
<para>
If you remove elements from the array, elements at the end of the array
are moved into the space previously occupied by the removed element.
This means that you should not rely on the index of particular elements
remaining the same. You should also be careful when deleting elements while
iterating over the array.
</para>
</note>

@array: a #GPtrArray.
@data: the pointer to remove.
@Returns: TRUE if the pointer is removed. FALSE if the pointer is not found
in the array.

<!-- ##### FUNCTION g_ptr_array_remove_index ##### -->
<para>
Removes the pointer at the given index from the pointer array.
</para>
<note>
<para>
If you remove elements from the array, elements at the end of the array
are moved into the space previously occupied by the removed element.
This means that you should not rely on the index of particular elements
remaining the same. You should also be careful when deleting elements while
iterating over the array.
</para>
</note>

@array: a #GPtrArray.
@index: the index of the pointer to remove.
@Returns: the pointer which was removed.

<!-- ##### FUNCTION g_ptr_array_set_size ##### -->
<para>
Sets the size of the array, expanding it if necessary.
New elements are set to NULL.
</para>

@array: a #GPtrArray.
@length: the new length of the pointer array.

<!-- ##### MACRO g_ptr_array_index ##### -->
<para>
Returns the pointer at the given index of the pointer array.
</para>

@array: a #GPtrArray.
@index: the index of the pointer to return.
@Returns: the pointer at the given index.

<!-- ##### FUNCTION g_ptr_array_free ##### -->
<para>
Frees all of the memory allocated for the pointer array.
</para>

@array: a #GPtrArray.
@free_seg: if TRUE the actual element data is freed as well.

