Replace set of en dashes with set of em dashes
We had used a pair of en dash somewhere we had meant to use a pair of
em dashes. Let's fix that.
diff --git a/src/const_eval.md b/src/const_eval.md
index b94e3d5..0b89aff 100644
--- a/src/const_eval.md
+++ b/src/const_eval.md
@@ -144,7 +144,7 @@
```
> [!NOTE]
- > In other words -- to focus on what's allowed rather than what's not allowed -- shared borrows of interior mutable data and mutable borrows are only allowed in a [const context] when the borrowed [place expression] is *transient*, *indirect*, or *static*.
+ > In other words --- to focus on what's allowed rather than what's not allowed --- shared borrows of interior mutable data and mutable borrows are only allowed in a [const context] when the borrowed [place expression] is *transient*, *indirect*, or *static*.
>
> A place expression is *transient* if it is a variable local to the current const context or an expression whose temporary scope is contained inside the current const context.
>
