Name
Pointer Arrays -- arrays of pointers to any type of data, which grow automatically as new
elements are added.
Synopsis
#include <glib.h>
struct GPtrArray;
GPtrArray* g_ptr_array_new (void);
GPtrArray* g_ptr_array_sized_new (guint reserved_size);
void g_ptr_array_add (GPtrArray *array,
gpointer data);
gboolean g_ptr_array_remove (GPtrArray *array,
gpointer data);
gpointer g_ptr_array_remove_index (GPtrArray *array,
guint index);
gboolean g_ptr_array_remove_fast (GPtrArray *array,
gpointer data);
gpointer g_ptr_array_remove_index_fast (GPtrArray *array,
guint index);
void g_ptr_array_sort (GPtrArray *array,
GCompareFunc compare_func);
void g_ptr_array_sort_with_data (GPtrArray *array,
GCompareDataFunc compare_func,
gpointer user_data);
void g_ptr_array_set_size (GPtrArray *array,
gint length);
#define g_ptr_array_index (array,index)
gpointer* g_ptr_array_free (GPtrArray *array,
gboolean free_seg);
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Description
Pointer Arrays are similar to Arrays but are used only for storing pointers.
Note:
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.
To create a pointer array, use g_ptr_array_new().
To add elements to a pointer array, use g_ptr_array_add().
To remove elements from a pointer array, use g_ptr_array_remove(),
g_ptr_array_remove_index() or g_ptr_array_remove_index_fast().
To access an element of a pointer array, use g_ptr_array_index().
To set the size of a pointer array, use g_ptr_array_set_size().
To free a pointer array, use g_ptr_array_free().
Example 1. Using a GPtrArray.
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);
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Details
struct GPtrArray
struct GPtrArray
{
gpointer *pdata;
guint len;
};
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Contains the public fields of a pointer array.
g_ptr_array_sized_new ()
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.
g_ptr_array_add ()
Adds a pointer to the end of the pointer array.
The array will grow in size automatically if necessary.
g_ptr_array_remove ()
Removes the first occurrence of the given pointer from the pointer array.
The following elements are moved down one place.
It returns TRUE if the pointer was removed, or FALSE if the pointer
was not found.
g_ptr_array_remove_index ()
Removes the pointer at the given index from the pointer array.
The following elements are moved down one place.
g_ptr_array_remove_fast ()
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().
It returns TRUE if the pointer was removed, or FALSE if the pointer
was not found.
g_ptr_array_remove_index_fast ()
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().
g_ptr_array_sort ()
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).
g_ptr_array_sort_with_data ()
Like g_ptr_array_sort(), but the comparison function has a user data argument.
g_ptr_array_set_size ()
Sets the size of the array, expanding it if necessary.
New elements are set to NULL.
g_ptr_array_index()
#define g_ptr_array_index(array,index) |
Returns the pointer at the given index of the pointer array.
g_ptr_array_free ()
Frees all of the memory allocated for the pointer array.