final review bits

crates/runtime/src/externref/no_gc.rs

@@ -30,6 +30,11 @@ impl Drop for VMExternRef {
 }
 
 impl VMExternRef {
+    /// This method is only available when the `gc` cargo feature is *disabled*.
+    pub fn assert_unreachable<T>(&self) -> T {
+        match self.0 {}
+    }
+
     pub fn as_raw(&self) -> *mut u8 {
         match self.0 {}
     }

crates/runtime/src/table.rs

@@ -2,6 +2,8 @@
 //!
 //! `Table` is to WebAssembly tables what `LinearMemory` is to WebAssembly linear memories.
 
+#![cfg_attr(feature = "gc", allow(irrefutable_let_patterns))]
+
 use crate::externref::VMExternRef;
 use crate::vmcontext::{VMFuncRef, VMTableDefinition};
 use crate::{SendSyncPtr, Store};
@@ -584,10 +586,6 @@ impl Drop for Table {
         let ty = self.element_type();
 
         // `funcref` tables don't need drops.
-        //
-        // This is an irrefutable pattern when the `gc` cargo feature is not
-        // enabled.
-        #[allow(irrefutable_let_patterns)]
         if let TableElementType::Func = ty {
             return;
         }

crates/wasmtime/src/runtime/func.rs

@@ -2027,9 +2027,8 @@ impl<T> Caller<'_, T> {
     /// Perform garbage collection of `ExternRef`s.
     ///
     /// Same as [`Store::gc`](crate::Store::gc).
-    ///
-    /// This method is only available when the `gc` cargo feature is enabled.
     #[cfg(feature = "gc")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "gc")))]
     pub fn gc(&mut self) {
         self.store.gc()
     }

crates/wasmtime/src/runtime/ref/no_gc_ref.rs

@@ -18,12 +18,12 @@ use wasmtime_runtime::VMExternRef;
 /// `gc` cargo feature to properly use this type.
 #[derive(Clone, Debug)]
 pub struct ExternRef {
-    pub(crate) _inner: Uninhabited,
+    _inner: Uninhabited,
 }
 
 impl ExternRef {
-    pub(crate) fn from_vm_extern_ref(_inner: VMExternRef) -> Self {
-        unreachable!()
+    pub(crate) fn from_vm_extern_ref(inner: VMExternRef) -> Self {
+        inner.assert_unreachable()
     }
 
     pub(crate) fn into_vm_extern_ref(self) -> VMExternRef {