[READY] The most unholy solution to 515 and 516 rustlibs (#28590)

* What in the heck is this

* Tweaks I should have made before opening the PR

* gah

* Fix if () spacing issue

* Use the proper package

rust/src/lib.rs

@@ -1,3 +1,11 @@
 mod logging;
 mod mapmanip;
 mod milla;
+
+#[cfg(all(not(feature = "byond-515"), not(feature = "byond-516")))]
+compile_error!("Please specify byond-515 or byond-516 as a feature to specify BYOND version.");
+
+#[cfg(all(feature = "byond-515", feature = "byond-516"))]
+compile_error!(
+    "Please specify ONLY byond-515 or bypnd-516 as a feature to specify BYOND version, not all features."
+);

rust/src/milla/api.rs

@@ -100,15 +100,29 @@ pub(crate) fn internal_create_environment(
 
 /// BYOND API for loading a block of turfs into MILLA with their default air.
 #[byondapi::bind]
-fn milla_load_turfs(data_property: ByondValue, low_corner: ByondValue, high_corner: ByondValue) -> eyre::Result<ByondValue> {
+fn milla_load_turfs(
+    data_property: ByondValue,
+    low_corner: ByondValue,
+    high_corner: ByondValue,
+) -> eyre::Result<ByondValue> {
     let property_ref = data_property.get_strid()?;
     for turf in byond_block(byond_xyz(&low_corner)?, byond_xyz(&high_corner)?)? {
         let (x, y, z) = byond_xyz(&turf)?.coordinates();
         let mut property = turf.read_var_id(property_ref)?;
         let data = property.get_list_values()?;
+
+        #[cfg(feature = "byond-516")]
+        property.decrement_tempref();
+
+        #[cfg(feature = "byond-515")]
         property.decrement_ref();
+
         if data.len() != 17 {
-            return Err(eyre!("data property has the wrong length: {} vs {}", data.len(), 17));
+            return Err(eyre!(
+                "data property has the wrong length: {} vs {}",
+                data.len(),
+                17
+            ));
         }
 
         internal_set_tile(