Function
GLibVariantnew_va
since: 2.24
Declaration
GVariant*
g_variant_new_va (
const gchar* format_string,
const gchar** endptr,
va_list* app
)
Description
This function is intended to be used by libraries based on
GVariant that want to provide g_variant_new()-like functionality
to their users.
The API is more general than g_variant_new() to allow a wider range
of possible uses.
format_string must still point to a valid format string, but it only
needs to be nul-terminated if endptr is NULL. If endptr is
non-NULL then it is updated to point to the first character past the
end of the format string.
app is a pointer to a #va_list. The arguments, according to
format_string, are collected from this #va_list and the list is left
pointing to the argument following the last.
Note that the arguments in app must be of the correct width for their
types specified in format_string when collected into the #va_list.
See the GVariant varargs documentation.
These two generalisations allow mixing of multiple calls to
g_variant_new_va() and g_variant_get_va() within a single actual
varargs call by the user.
The return value will be floating if it was a newly created GVariant
instance (for example, if the format string was “(ii)”). In the case
that the format_string was ‘*’, ‘?’, ‘r’, or a format starting with
‘@’ then the collected GVariant pointer will be returned unmodified,
without adding any additional references.
In order to behave correctly in all cases it is necessary for the
calling function to g_variant_ref_sink() the return result before
returning control to the user that originally provided the pointer.
At this point, the caller will have their own full reference to the
result. This can also be done by adding the result to a container,
or by passing it to another g_variant_new() call.
Available since: 2.24
This function is not directly available to language bindings.
Parameters
format_string-
Type:
const gchar*A string that is prefixed with a format string.
The data is owned by the caller of the function. The value is a NUL terminated UTF-8 string. endptr-
Type:
const gchar**Location to store the end pointer, or
NULL.The argument can be NULL.The data is owned by the caller of the function. The value is a NUL terminated UTF-8 string. app-
Type:
va_list*A pointer to a #va_list.
The data is owned by the caller of the function.
Return value
Type: GVariant
A new, usually floating, GVariant.
| The caller of the function takes ownership of the data, and is responsible for freeing it. |