/* GObject - GLib Type, Object, Parameter and Signal Library

  * Copyright (C) 1997-1999, 2000-2001 Tim Janik and Red Hat, Inc.

  * Portions copyright (c) 2006-2009 Nokia Corporation.  All rights reserved.

  * This library is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public

  * License as published by the Free Software Foundation; either

  * version 2 of the License, or (at your option) any later version.

  *

  * This library is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  * Lesser General Public License for more details.

  *

  * You should have received a copy of the GNU Lesser General

  * Public License along with this library; if not, write to the

  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,

  * Boston, MA 02111-1307, USA.

  *

  * gvalue.h: generic GValue functions

  */

 #if !defined (__GLIB_GOBJECT_H_INSIDE__) && !defined (GOBJECT_COMPILATION)

 #error "Only <glib-object.h> can be included directly."

 #endif

 #ifndef __G_VALUE_H__

 #define __G_VALUE_H__

 #include	<gobject/gtype.h>

 G_BEGIN_DECLS

 /* --- type macros --- */

 /**

  * G_TYPE_IS_VALUE:

  * @type: A #GType value.

  * 

  * Checks whether the passed in type ID can be used for g_value_init().

  * That is, this macro checks whether this type provides an implementation

  * of the #GTypeValueTable functions required for a type to create a #GValue of.

  * 

  * Returns: Whether @type is suitable as a #GValue type.

  */

 #define	G_TYPE_IS_VALUE(type)		(g_type_check_is_value_type (type))

 /**

  * G_IS_VALUE:

  * @value: A #GValue structure.

  * 

  * Checks if @value is a valid and initialized #GValue structure.

  *

  * Returns: %TRUE on success.

  */

 #define	G_IS_VALUE(value)		(G_TYPE_CHECK_VALUE (value))

 /**

  * G_VALUE_TYPE:

  * @value: A #GValue structure.

  * 

  * Get the type identifier of @value.

  *

  * Returns: the #GType.

  */

 #define	G_VALUE_TYPE(value)		(((GValue*) (value))->g_type)

 /**

  * G_VALUE_TYPE_NAME:

  * @value: A #GValue structure.

  *

  * Gets the the type name of @value. 

  *

  * Returns: the type name.

  */

 #define	G_VALUE_TYPE_NAME(value)	(g_type_name (G_VALUE_TYPE (value)))

 /**

  * G_VALUE_HOLDS:

  * @value: A #GValue structure.

  * @type: A #GType value.

  * 

  * Checks if @value holds (or contains) a value of @type.

  * This macro will also check for @value != %NULL and issue a

  * warning if the check fails.

  *

  * Returns: %TRUE if @value holds the @type.

  */

 #define G_VALUE_HOLDS(value,type)	(G_TYPE_CHECK_VALUE_TYPE ((value), (type)))

 /* --- typedefs & structures --- */

 /**

  * GValueTransform:

  * @src_value: Source value.

  * @dest_value: Target value.

  * 

  * The type of value transformation functions which can be registered with

  * g_value_register_transform_func().

  */

 typedef void (*GValueTransform) (const GValue *src_value,

 				 GValue       *dest_value);

 /**

  * GValue:

  * 

  * An opaque structure used to hold different types of values.

  * The data within the structure has protected scope: it is accessible only

  * to functions within a #GTypeValueTable structure, or implementations of

  * the g_value_*() API. That is, code portions which implement new fundamental

  * types.

  * #GValue users can not make any assumptions about how data is stored

  * within the 2 element @data union, and the @g_type member should

  * only be accessed through the G_VALUE_TYPE() macro.

  */

 struct _GValue

 {

   /*< private >*/

   GType		g_type;

   /* public for GTypeValueTable methods */

   union {

     gint	v_int;

     guint	v_uint;

     glong	v_long;

     gulong	v_ulong;

     gint64      v_int64;

     guint64     v_uint64;

     gfloat	v_float;

     gdouble	v_double;

     gpointer	v_pointer;

   } data[2];

 };

 /* --- prototypes --- */

 IMPORT_C GValue*         g_value_init	   	(GValue       *value,

 					 GType         g_type);

 IMPORT_C void            g_value_copy    	(const GValue *src_value,

 					 GValue       *dest_value);

 IMPORT_C GValue*         g_value_reset   	(GValue       *value);

 IMPORT_C void            g_value_unset   	(GValue       *value);

 IMPORT_C void		g_value_set_instance	(GValue	      *value,

 					 gpointer      instance);

 /* --- private --- */

 IMPORT_C gboolean	g_value_fits_pointer	(const GValue *value);

 IMPORT_C gpointer	g_value_peek_pointer	(const GValue *value);

 /* --- implementation details --- */

 IMPORT_C gboolean g_value_type_compatible	(GType		 src_type,

 					 GType		 dest_type);

 IMPORT_C gboolean g_value_type_transformable	(GType           src_type,

 					 GType           dest_type);

 IMPORT_C gboolean g_value_transform		(const GValue   *src_value,

 					 GValue         *dest_value);

 IMPORT_C void	g_value_register_transform_func	(GType		 src_type,

 					 GType		 dest_type,

 					 GValueTransform transform_func);

 #define G_VALUE_NOCOPY_CONTENTS		(1 << 27)

 G_END_DECLS

 #endif /* __G_VALUE_H__ */