GScanner: should explicitly document modifiable fields (value, next_value, ...)
Submitted by Tommi Komulainen
It is unclear, for example, whether g_strcanon(scanner->value.v_identifier) is legal or value should be considered read only.
Only user_data and max_parse_errors are explicitly documented to be read-write and few fields as private. For the rest the rules are somewhat ambiguous.
See also bug 165693