fixup! Add DynStorageAlloc using FnOnce

Author: robin-nitrokey

src/lib.rs

@@ -1,4 +1,5 @@
 #![cfg_attr(not(test), no_std)]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
 // FIXME
 #![allow(clippy::missing_safety_doc)]
 

src/object_safe.rs

@@ -243,6 +243,9 @@ impl dyn DynStorage + '_ {
 }
 
 #[cfg(feature = "alloc")]
+/// Extension trait for [`DynStorage`][] that requires `alloc`.
+///
+/// This extension trait uses owned `FnOnce` callbacks instead of references to `FnMut`.
 pub trait DynStorageAlloc: DynStorage {
     fn mount_and_then_unit_boxed(&mut self, f: BoxedFilesystemCallback<'_>) -> Result<()>;
 }
@@ -256,7 +259,10 @@ impl<T: Storage> DynStorageAlloc for T {
 
 #[cfg(feature = "alloc")]
 impl dyn DynStorageAlloc + '_ {
-    pub fn mount_and_then_boxed<R>(&mut self, f: BoxedFilesystemCallback<'_, R>) -> Result<R> {
+    pub fn mount_and_then_once<F, R>(&mut self, f: F) -> Result<R>
+    where
+        F: FnOnce(&dyn DynFilesystem) -> Result<R>,
+    {
         let mut result = Err(Error::IO);
         self.mount_and_then_unit_boxed(alloc::boxed::Box::new(|fs| {
             result = Ok(f(fs)?);