Parses an enum type and stores the result in @value.
If @str does not match the nick name of any of the possible values
for the enum and is not an integer, %FALSE is returned, a warning
is issued if @warn is %TRUE, and a string representing the list of
possible values is stored in @possible_values. The list is
slash-separated, eg. "none/start/middle/end".
If failed and @possible_values is not %NULL, returned string should
be freed using g_free().
Parses an enum type and stores the result in @value.
If @str does not match the nick name of any of the possible values for the enum and is not an integer, %FALSE is returned, a warning is issued if @warn is %TRUE, and a string representing the list of possible values is stored in @possible_values. The list is slash-separated, eg. "none/start/middle/end".
If failed and @possible_values is not %NULL, returned string should be freed using g_free().