Calls the given function for each data element of the datalist. The
function is called with each data element's GQuark id and data,
together with the given user_data parameter. Note that this
function is NOT thread-safe. So unless datalist can be protected
from any modifications during invocation of this function, it should
not be called.
Calls the given function for each data element of the datalist. The function is called with each data element's GQuark id and data, together with the given user_data parameter. Note that this function is NOT thread-safe. So unless datalist can be protected from any modifications during invocation of this function, it should not be called.