glib/docs/reference/gobject/value-collection.md

Title: Value Collection SPDX-License-Identifier: LGPL-2.1-or-later SPDX-FileCopyrightText: 2005 Matthias Clasen

Value Collection

GLib provides a set of macros for the varargs parsing support needed in variadic GObject functions such as [ctor@GObject.Object.new] or [method@GObject.Object.set]

They currently support the collection of integral types, floating point types and pointers.

Macros

G_VALUE_COLLECT_INIT(value, _value_type, var_args, flags, __error)

Collects a variable argument value from a va_list.

We have to implement the varargs collection as a macro, because on some systems va_list variables cannot be passed by reference.

Since: 2.24

G_VALUE_COLLECT_INIT2(value, g_vci_vtab, _value_type, var_args, flags, __error)

A variant of G_VALUE_COLLECT_INIT that provides the [struct@GObject.TypeValueTable] to the caller.

Since: 2.74

G_VALUE_COLLECT(value, var_args, flags, __error)

Collects a variable argument value from a va_list.

We have to implement the varargs collection as a macro, because on some systems va_list variables cannot be passed by reference.

Note: If you are creating the value argument just before calling this macro, you should use the G_VALUE_COLLECT_INIT variant and pass the uninitialized GValue. That variant is faster than G_VALUE_COLLECT.

G_VALUE_COLLECT_SKIP(_value_type, var_args)

Skip an argument of type _value_type from var_args.

G_VALUE_LCOPY(value, var_args, flags, __error)

Stores a value’s value into one or more argument locations from a va_list.

This is the inverse of G_VALUE_COLLECT().

G_VALUE_COLLECT_FORMAT_MAX_LENGTH

The maximal number of [type@GObject.TypeCValue]s which can be collected for a single GValue.