/* 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__ */