`IniGroup::GetItem()` returns nullptr if the item does not exist, but does not if the create parameter is set to true. Resolve CodeQL warnings with `GetOrCreateItem()` which returns a reference to the item instead.
This is using a non-intrusive type-traits like templated system, which
allows compile-time validation that the command table and the command
enum match up.
Now you can use things like `set server_game_type public` instead of having to
guess the number, which would not be written into the configuration file nor
would it be shown when doing `set server_game_type`.
This reduced the load on compilers, as currently for example MacOS
doesn't like the huge settings-tables.
Additionally, nobody can find settings, as the list is massive and
unordered. By splitting it, it becomes a little bit more sensible.
We won't be able to make it fully self-descriptive (looking at you
MAP-chunks), but anything else can. With this framework, we can
add headers for each chunk explaining how each chunk looks like
in detail.
They also will all be tables, making it a lot easier to read in
external tooling, and opening the way to consider a database
(like SQLite) to use as savegame format.
Lastly, with the headers in the savegame, you can freely add
fields without needing a savegame version bump; older versions
of OpenTTD will simply ignore the new field. This also means
we can remove all the SLE_CONDNULL, as they are irrelevant.
The next few commits will start using this framework.
We often ask people for their openttd.cfg, which now includes their
passwords, usernames, etc. It is easy for people to overlook this,
unwillingly sharing information they shouldn't.
By splitting this information over either private.cfg or secrets.cfg,
we make it more obvious they shouldn't be sharing those files, and
hint to what is inside them.
Instead of creating the object on heap and use a pointer, create
the object on stack and use a guaranteed-not-null pointer.
The size of IniFile doesn't warrent the forcing to heap.
Additionally, use a subclass instead of a function to do some
initial bookkeeping on an IniFile meant to read a configuration.
With std::variant all memory can be figured out at compile time, so the compiler needs to keep track of fewer elements. It also saves out a unique_ptr and its memory management, over a slight impact for resolving a setting.
One UpdateServiceInterval has two parameters to update the service interval for a vehicle type, the other for all vehicle types at once. Rename the latter to help with function resolution for the introduction of variants.
This makes it easier to spot chunks that have a save_proc that
is a nullptr, but also prevents confusion, where it looks like
the CH_ type of a chunk has influence on how it is being read.
It is not, it is only used for saving.
Jonathan G Rennison