docs: grammar fix

diff --git a/src/doc/trpl/compound-data-types.md b/src/doc/trpl/compound-data-types.md
index f584fe8d7a323347531964da56467d8aeae5ff1c..0616f094e376e0b3f3af6398b01ec2738cf5808e 100644 (file)
--- a/src/doc/trpl/compound-data-types.md
+++ b/src/doc/trpl/compound-data-types.md
@@ -297,7 +297,7 @@ enum StringResult {
 }
 ```
 Where a `StringResult` is either a `StringResult::StringOK`, with the result of
-a computation, or an `StringResult::ErrorReason` with a `String` explaining
+a computation, or a `StringResult::ErrorReason` with a `String` explaining
 what caused the computation to fail. These kinds of `enum`s are actually very
 useful and are even part of the standard library.