Update maintaining-std.md

KodrAus · web-flow · commit 7861c366455c · 2020-09-07T10:52:08.000+10:00
diff --git a/src/libs/maintaining-std.md b/src/libs/maintaining-std.md
@@ -204,7 +204,7 @@ struct OptionCell<T> {
 }
 ```
 
-Types in the standard library that use the internal `Unique<T>` will don't need a `PhantomData` marker field. That's taken care of for them by `Unique<T>`.
+Types in the standard library that use the internal `Unique<T>` don't need a `PhantomData` marker field. That's taken care of for them by `Unique<T>`.
 
 ### How could `mem` break assumptions?
 

Original file line number	Diff line number	Diff line change
`@@ -204,7 +204,7 @@ struct OptionCell<T> {`
`204`	`204`	`}`
`205`	`205`	```
`206`	`206`
`207`		-Types in the standard library that use the internal `Unique<T>` will don't need a `PhantomData` marker field. That's taken care of for them by `Unique<T>`.
	`207`	+Types in the standard library that use the internal `Unique<T>` don't need a `PhantomData` marker field. That's taken care of for them by `Unique<T>`.
`208`	`208`
`209`	`209`	### How could `mem` break assumptions?
`210`	`210`