Fix #2612: adjust readable trait to allow try_peek (#2714)

* Fix #2612: adjust readable trait to allow try_peek

Our implementation for Readable was inconsistent.
We had a try_unchecked variant for read but not for peek.
This resolves that by making a breaking change to the
Readable interface.

* fix doctests too

packages/signals/src/global/memo.rs

@@ -1,7 +1,7 @@
 use crate::{read::Readable, Memo, ReadableRef};
 use crate::{read_impls, GlobalKey};
 use dioxus_core::prelude::ScopeId;
-use generational_box::UnsyncStorage;
+use generational_box::{BorrowResult, UnsyncStorage};
 use std::ops::Deref;
 
 use crate::Signal;
@@ -75,8 +75,8 @@ impl<T: PartialEq + 'static> Readable for GlobalMemo<T> {
     }
 
     #[track_caller]
-    fn peek_unchecked(&self) -> ReadableRef<'static, Self> {
-        self.memo().peek_unchecked()
+    fn try_peek_unchecked(&self) -> BorrowResult<ReadableRef<'static, Self>> {
+        self.memo().try_peek_unchecked()
     }
 }
 

packages/signals/src/global/signal.rs

@@ -2,7 +2,7 @@ use crate::{read::Readable, ReadableRef};
 use crate::{write::Writable, GlobalKey};
 use crate::{WritableRef, Write};
 use dioxus_core::{prelude::ScopeId, Runtime};
-use generational_box::UnsyncStorage;
+use generational_box::{BorrowResult, UnsyncStorage};
 use std::ops::Deref;
 
 use super::get_global_context;
@@ -110,8 +110,8 @@ impl<T: 'static> Readable for GlobalSignal<T> {
     }
 
     #[track_caller]
-    fn peek_unchecked(&self) -> ReadableRef<'static, Self> {
-        self.signal().peek_unchecked()
+    fn try_peek_unchecked(&self) -> BorrowResult<ReadableRef<'static, Self>> {
+        self.signal().try_peek_unchecked()
     }
 }