GObject – 2.0: Value Collection
Description: Reference for GObject-2.0: Value Collection

#### Value Collection

GLib provides a set of macros for the varargs parsing support needed in variadic GObject functions such as `g_object_new()` or `g_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 `GTypeValueTable` 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 `GTypeCValue`s which can be collected for a single `GValue`.