It is an error to call this function in any way that would create an inconsistent value to be constructed. Some examples of this are putting different types of items into an array, putting the wrong types or number of items in a tuple, putting more than one value into a variant, etc.
value is a floating reference (see g_variant_ref_sink()),
builder instance takes ownership of
Available since: 2.24
The data is owned by the caller of the method.