C++ G_IS_VALUE函數代碼示例

gboolean
_midgard_dbobject_get_property (MidgardDBObject *self, const gchar *name, GValue *value)
{
	g_return_val_if_fail (self != NULL, FALSE);
	g_return_val_if_fail (name != NULL, FALSE);
	g_return_val_if_fail (G_IS_VALUE (value), FALSE);

	if (!self->dbpriv->datamodel)
		return FALSE;

	GdaDataModel *model = GDA_DATA_MODEL (self->dbpriv->datamodel);
	if (!model || (model && !GDA_IS_DATA_MODEL (model)))
		return FALSE;

	gint col_idx = gda_data_model_get_column_index (model, name);
	if (col_idx == -1)
		return FALSE;

	const GValue *src_val = gda_data_model_get_value_at (model, col_idx, self->dbpriv->row, NULL);
	if (!src_val)
		return FALSE;

	if (!G_IS_VALUE (src_val) 
			|| (G_IS_VALUE (src_val) 
				&& G_VALUE_TYPE (src_val) == GDA_TYPE_NULL)) {
		/* NULL fetched from underlying field */
		if (G_VALUE_HOLDS_STRING (value)) {
			g_value_set_string (value, "");
			return TRUE;
		}
		g_warning ("Can not find value for given '%s' property \n", name);
		return FALSE;
	}

	if (G_VALUE_TYPE (src_val) != G_VALUE_TYPE (value))
		g_value_transform (src_val, value);
	else 
		g_value_copy (src_val, value);

	if (G_VALUE_HOLDS_STRING (value) && g_value_get_string (value) == NULL)
		g_value_set_string (value, "");

	return TRUE;
}

static void
destroy_gvalue(GValue *value)
{
	if (value != NULL)
	{
		g_return_if_fail(G_IS_VALUE(value));
		g_value_reset(value);
		g_free(value);
	}
}

gchar *GstUtils::gvalue_serialize(const GValue *val) {
  if (!G_IS_VALUE(val))
    return nullptr;
  gchar *val_str;
  if (G_VALUE_TYPE(val) == G_TYPE_STRING)
    val_str = g_strdup(g_value_get_string(val));
  else
    val_str = gst_value_serialize(val);
  return val_str;
}

coil_expandable_value_equals(const GValue  *v1,
                             const GValue  *v2,
                             GError       **error) /* no need */
{
  g_return_val_if_fail(G_IS_VALUE(v1), FALSE);
  g_return_val_if_fail(G_IS_VALUE(v2), FALSE);
  g_return_val_if_fail(error == NULL || *error == NULL, FALSE);

  const CoilExpandable *x1, *x2;

  if (!(G_VALUE_HOLDS(v1, COIL_TYPE_EXPANDABLE)
    && G_VALUE_HOLDS(v2, COIL_TYPE_EXPANDABLE)))
    return FALSE;

  x1 = COIL_EXPANDABLE(g_value_get_object(v1));
  x2 = COIL_EXPANDABLE(g_value_get_object(v2));

  return coil_expandable_equals(x1, x2, error);
}

const gchar *
conting_attributes_get_string(ContingAttributes *self, const gchar *name)
{
    const GValue *value;

    value = conting_attributes_get_value(self, name);

    g_return_val_if_fail(value != NULL && G_IS_VALUE(value), NULL);

    return g_value_get_string(value);
}

static void
gst_lfo_control_source_reset (GstLFOControlSource * self)
{
  GstControlSource *csource = GST_CONTROL_SOURCE (self);

  csource->get_value = NULL;
  csource->get_value_array = NULL;

  self->priv->type = self->priv->base = G_TYPE_INVALID;

  if (G_IS_VALUE (&self->priv->minimum_value))
    g_value_unset (&self->priv->minimum_value);
  if (G_IS_VALUE (&self->priv->maximum_value))
    g_value_unset (&self->priv->maximum_value);

  if (G_IS_VALUE (&self->priv->amplitude))
    g_value_unset (&self->priv->amplitude);
  if (G_IS_VALUE (&self->priv->offset))
    g_value_unset (&self->priv->offset);
}

static void
value_free (GDataFreebaseTopicValue *value)
{
	if (G_IS_VALUE (&value->value))
		g_value_unset (&value->value);
	g_free (value->text);
	g_free (value->lang);
	g_free (value->creator);
	g_free (value->property);
	g_slice_free (GDataFreebaseTopicValue, value);
}

static VALUE
gobj_new_ensure(struct param_setup_arg* arg)
{
    guint i;
    g_type_class_unref(arg->gclass);
    for (i = 0; i < arg->param_size; i++) {
        if (G_IS_VALUE(&arg->params[i].value))
            g_value_unset(&arg->params[i].value);
    }
    return Qnil;
}

/**
 * g_value_fits_pointer:
 * @value: An initialized #GValue structure.
 *
 * Determines if @value will fit inside the size of a pointer value.
 * This is an internal function introduced mainly for C marshallers.
 *
 * Returns: %TRUE if @value will fit inside a pointer value.
 */
gboolean
g_value_fits_pointer (const GValue *value)
{
    GTypeValueTable *value_table;

    g_return_val_if_fail (G_IS_VALUE (value), FALSE);

    value_table = g_type_value_table_peek (G_VALUE_TYPE (value));

    return value_table->value_peek_pointer != NULL;
}

gboolean property_context_from_gvalue(PropertyContext * ctx, GValue * value)
{
    if (ctx == NULL) {
        return FALSE;
    }
    if (!G_IS_VALUE(value)) {
        return FALSE;
    }
    g_value_copy(value, &(ctx->value));
    return TRUE;
}

static void
finalize (GObject *object)
{
	NMVPNPlugin *plugin = NM_VPN_PLUGIN (object);
	NMVPNPluginPrivate *priv = NM_VPN_PLUGIN_GET_PRIVATE (plugin);

	nm_vpn_plugin_set_connection (plugin, NULL);
	g_free (priv->dbus_service_name);

	if (G_IS_VALUE (&priv->banner))
		g_value_unset (&priv->banner);
	if (G_IS_VALUE (&priv->tundev))
		g_value_unset (&priv->tundev);
	if (G_IS_VALUE (&priv->gateway))
		g_value_unset (&priv->gateway);
	if (G_IS_VALUE (&priv->mtu))
		g_value_unset (&priv->mtu);

	G_OBJECT_CLASS (nm_vpn_plugin_parent_class)->finalize (object);
}

static SteadyflowCoreIDownloadFile* steadyflow_file_list_controller_file_from_iter (SteadyflowFileListController* self, GtkTreeIter* iter) {
	SteadyflowCoreIDownloadFile* result = NULL;
	GValue value = {0};
	GtkListStore* _tmp0_;
	GtkTreeIter _tmp1_;
	GValue _tmp2_ = {0};
	GObject* _tmp3_ = NULL;
	SteadyflowCoreIDownloadFile* _tmp4_;
	g_return_val_if_fail (self != NULL, NULL);
	g_return_val_if_fail (iter != NULL, NULL);
	_tmp0_ = self->priv->model;
	_tmp1_ = *iter;
	gtk_tree_model_get_value ((GtkTreeModel*) _tmp0_, &_tmp1_, 0, &_tmp2_);
	G_IS_VALUE (&value) ? (g_value_unset (&value), NULL) : NULL;
	value = _tmp2_;
	_tmp3_ = g_value_get_object (&value);
	_tmp4_ = _g_object_ref0 (STEADYFLOW_CORE_IDOWNLOAD_FILE (_tmp3_));
	result = _tmp4_;
	G_IS_VALUE (&value) ? (g_value_unset (&value), NULL) : NULL;
	return result;
}

static GValue *
test_gvalue_callback (GObject *object, const GValue *v)
{
  GValue *ret = g_malloc0 (sizeof (GValue));

  g_return_val_if_fail (G_IS_OBJECT (object), NULL);
  g_return_val_if_fail (G_IS_VALUE (v), NULL);

  g_value_init (ret, G_VALUE_TYPE (v));
  g_value_copy (v, ret);
  return ret;
}

/**
 * gnc_value_get_guid
 *
 * @param value a @c GValue whose value we want to get.
 *
 * @return the value stored in @a value
 */
const GncGUID*
gnc_value_get_guid (const GValue *value)
{
    GncGUID *val;

    g_return_val_if_fail (value && G_IS_VALUE (value), NULL);
    g_return_val_if_fail (GNC_VALUE_HOLDS_GUID (value), NULL);

    val = (GncGUID*) g_value_get_boxed (value);

    return val;
}

gboolean GN_value_unset(int ARI, ei_x_buff *XBUF, char *B, int *I){

  GValue* object;

  /* no return value */

  if ( ! gn_check_arity(XBUF, 1, ARI) ) return FALSE;
  if ( ! gn_get_arg_struct(XBUF, B, I, "GValue", (void**)&object) ) return FALSE;
  if ( G_IS_VALUE(object) ) g_value_unset(object);
  gn_put_void(XBUF);
  return TRUE;
}