Description
GBoxed is a generic wrapper mechanism for arbitrary C structures. The only
thing the type system needs to know about the structures is how to copy them
(a GBoxedCopyFunc) and how to free them (a GBoxedFreeFunc) — beyond that
they are treated as opaque chunks of memory.
Boxed types are useful for simple value-holder structures like rectangles or
points. They can also be used for wrapping structures defined in non-GObject
based libraries. They allow arbitrary structures to be handled in a uniform
way, allowing uniform copying (or referencing) and freeing (or unreferencing)
of them, and uniform representation of the type of the contained structure.
In turn, this allows any type which can be boxed to be set as the data in a
GValue, which allows for polymorphic handling of a much wider range of data
types, and hence usage of such types as GObject property values.
GBoxed is designed so that reference counted types can be boxed. Use the
type’s ‘ref’ function as the GBoxedCopyFunc, and its ‘unref’ function as the
GBoxedFreeFunc. For example, for GBytes, the GBoxedCopyFunc is
g_bytes_ref(), and the GBoxedFreeFunc is g_bytes_unref().
Functions
GBoxedCopyFunc ()
gpointer
(*GBoxedCopyFunc) (gpointer boxed);
This function is provided by the user and should produce a copy
of the passed in boxed structure.
Returns
The newly created copy of the boxed structure.
[not nullable]
GBoxedFreeFunc ()
void
(*GBoxedFreeFunc) (gpointer boxed);
This function is provided by the user and should free the boxed
structure passed.
g_boxed_copy ()
gpointer
g_boxed_copy (GType boxed_type,
gconstpointer src_boxed);
Provide a copy of a boxed structure src_boxed
which is of type boxed_type
.
Returns
The newly created copy of the boxed
structure.
[transfer full][not nullable]
g_boxed_free ()
void
g_boxed_free (GType boxed_type,
gpointer boxed);
Free the boxed structure boxed
which is of type boxed_type
.
g_boxed_type_register_static ()
GType
g_boxed_type_register_static (const gchar *name,
GBoxedCopyFunc boxed_copy,
GBoxedFreeFunc boxed_free);
This function creates a new G_TYPE_BOXED derived type id for a new
boxed type with name name
. Boxed type handling functions have to be
provided to copy and free opaque boxed structures of this type.
g_pointer_type_register_static ()
GType
g_pointer_type_register_static (const gchar *name);
Creates a new G_TYPE_POINTER derived type id for a new
pointer type with name name
.
Types and Values
G_TYPE_HASH_TABLE
#define G_TYPE_HASH_TABLE (g_hash_table_get_type ())
The GType for a boxed type holding a GHashTable reference.
Since: 2.10
G_TYPE_DATE
#define G_TYPE_DATE (g_date_get_type ())
The GType for GDate.
G_TYPE_GSTRING
#define G_TYPE_GSTRING (g_gstring_get_type ())
The GType for GString.
G_TYPE_REGEX
#define G_TYPE_REGEX (g_regex_get_type ())
The GType for a boxed type holding a GRegex reference.
Since: 2.14
G_TYPE_MATCH_INFO
#define G_TYPE_MATCH_INFO (g_match_info_get_type ())
The GType for a boxed type holding a GMatchInfo reference.
Since: 2.30
G_TYPE_ARRAY
#define G_TYPE_ARRAY (g_array_get_type ())
The GType for a boxed type holding a GArray reference.
Since: 2.22
G_TYPE_BYTE_ARRAY
#define G_TYPE_BYTE_ARRAY (g_byte_array_get_type ())
The GType for a boxed type holding a GByteArray reference.
Since: 2.22
G_TYPE_PTR_ARRAY
#define G_TYPE_PTR_ARRAY (g_ptr_array_get_type ())
The GType for a boxed type holding a GPtrArray reference.
Since: 2.22
G_TYPE_BYTES
#define G_TYPE_BYTES (g_bytes_get_type ())
The GType for GBytes.
Since: 2.32
G_TYPE_VARIANT_TYPE
#define G_TYPE_VARIANT_TYPE (g_variant_type_get_gtype ())
The GType for a boxed type holding a GVariantType.
Since: 2.24
G_TYPE_ERROR
#define G_TYPE_ERROR (g_error_get_type ())
The GType for a boxed type holding a GError.
Since: 2.26
G_TYPE_DATE_TIME
#define G_TYPE_DATE_TIME (g_date_time_get_type ())
The GType for a boxed type holding a GDateTime.
Since: 2.26
G_TYPE_TIME_ZONE
#define G_TYPE_TIME_ZONE (g_time_zone_get_type ())
The GType for a boxed type holding a GTimeZone.
Since: 2.34
G_TYPE_IO_CHANNEL
#define G_TYPE_IO_CHANNEL (g_io_channel_get_type ())
The GType for GIOChannel.
G_TYPE_IO_CONDITION
#define G_TYPE_IO_CONDITION (g_io_condition_get_type ())
The GType for GIOCondition.
G_TYPE_VARIANT_BUILDER
#define G_TYPE_VARIANT_BUILDER (g_variant_builder_get_type ())
The GType for a boxed type holding a GVariantBuilder.
Since: 2.30
G_TYPE_VARIANT_DICT
#define G_TYPE_VARIANT_DICT (g_variant_dict_get_type ())
The GType for a boxed type holding a GVariantDict.
Since: 2.40
G_TYPE_KEY_FILE
#define G_TYPE_KEY_FILE (g_key_file_get_type ())
The GType for a boxed type holding a GKeyFile.
Since: 2.32
G_TYPE_MAIN_CONTEXT
#define G_TYPE_MAIN_CONTEXT (g_main_context_get_type ())
The GType for a boxed type holding a GMainContext.
Since: 2.30
G_TYPE_MAIN_LOOP
#define G_TYPE_MAIN_LOOP (g_main_loop_get_type ())
The GType for a boxed type holding a GMainLoop.
Since: 2.30
G_TYPE_MAPPED_FILE
#define G_TYPE_MAPPED_FILE (g_mapped_file_get_type ())
The GType for a boxed type holding a GMappedFile.
Since: 2.40
G_TYPE_MARKUP_PARSE_CONTEXT
#define G_TYPE_MARKUP_PARSE_CONTEXT (g_markup_parse_context_get_type ())
The GType for a boxed type holding a GMarkupParseContext.
Since: 2.36
G_TYPE_SOURCE
#define G_TYPE_SOURCE (g_source_get_type ())
The GType for a boxed type holding a GSource.
Since: 2.30
G_TYPE_POLLFD
#define G_TYPE_POLLFD (g_pollfd_get_type ())
The GType for a boxed type holding a GPollFD.
Since: 2.36
G_TYPE_THREAD
#define G_TYPE_THREAD (g_thread_get_type ())
The GType for a boxed type holding a GThread.
Since: 2.36
G_TYPE_OPTION_GROUP
#define G_TYPE_OPTION_GROUP (g_option_group_get_type ())
The GType for a boxed type holding a GOptionGroup.
Since: 2.44