docs/reference/glib/tmpl/arrays_pointer.sgml

<!-- ##### 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(),
g_ptr_array_remove_index() or g_ptr_array_remove_index_fast().
</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 <structname>GPtrArray</structname></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 &percnt;p instead of &percnt;p\n",
             g_ptr_array_index (gparray, 0), string1);

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

<!-- ##### SECTION See_Also ##### -->
<para>

</para>

<!-- ##### SECTION Stability_Level ##### -->


<!-- ##### STRUCT GPtrArray ##### -->
<para>
Contains the public fields of a pointer array.
</para>

@pdata: points to the array of pointers, which may be moved when the array grows.
@len: number of pointers in the array.

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

@Returns: the new #GPtrArray.


<!-- ##### FUNCTION g_ptr_array_sized_new ##### -->
<para>
Creates a new #GPtrArray with @reserved_size pointers
preallocated. This avoids frequent reallocation, if you are going to
add many pointers to the array. Note however that the size of the
array is still 0.
</para>

@reserved_size: number of pointers preallocated.
@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 the given pointer from the pointer array.
The following elements are moved down one place.
</para>
<para>
It returns %TRUE if the pointer was removed, or %FALSE if the pointer
was not found.
</para>

@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.
The following elements are moved down one place.
</para>

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


<!-- ##### FUNCTION g_ptr_array_remove_fast ##### -->
<para>
Removes the first occurrence of the given pointer from the pointer array.
The last element in the array is used to fill in the space, so this function
does not preserve the order of the array. But it is faster than
g_ptr_array_remove().
</para>
<para>
It returns %TRUE if the pointer was removed, or %FALSE if the pointer
was not found.
</para>

@array: a #GPtrArray.
@data: the pointer to remove.
@Returns: %TRUE if the pointer was found in the array.


<!-- ##### FUNCTION g_ptr_array_remove_index_fast ##### -->
<para>
Removes the pointer at the given index from the pointer array.
The last element in the array is used to fill in the space, so this function
does not preserve the order of the array. But it is faster than
g_ptr_array_remove_index().
</para>

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


<!-- ##### FUNCTION g_ptr_array_remove_range ##### -->
<para>
Removes the given number of bytes starting at the given index from a
#GPtrArray.  The following elements are moved to close the gap.
</para>

@array: a @GPtrArray.
@index_: the index of the first pointer to remove.
@length: the number of pointers to remove.
@Since: 2.4


<!-- ##### FUNCTION g_ptr_array_sort ##### -->
<para>
Sorts the array, using @compare_func which should be a qsort()-style comparison
function (returns -1 for first arg is less than second arg, 0 for equal, 1 if
first arg is greater than second arg).
</para>
<note><para>
The comparison function for g_ptr_array_sort() doesn't take the pointers from the array as arguments, 
it takes pointers to the pointers in the array.
</para></note>

@array: a #GPtrArray.
@compare_func: comparison function.


<!-- ##### FUNCTION g_ptr_array_sort_with_data ##### -->
<para>
Like g_ptr_array_sort(), but the comparison function has a user data argument.
</para>
<note><para>
The comparison function for g_ptr_array_sort_with_data() doesn't take the pointers from the array as arguments, 
it takes pointers to the pointers in the array.
</para></note>

@array: a #GPtrArray.
@compare_func: comparison function.
@user_data: data to pass to @compare_func.


<!-- ##### 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.
@Returns: 


<!-- ##### FUNCTION g_ptr_array_foreach ##### -->
<para>

</para>

@array: 
@func: 
@user_data: