Explicitly state result of compound assignment

tlyu · tlyu · commit 0a626ce599bc · 2021-05-04T14:08:00.000-05:00
The existing text implies but doesn't explicitly say that
compound assignment produces the unit value. A reader could also
infer it from the signatures of the compound assignment trait
functions, but it seems better to be explicit.
diff --git a/src/expressions/operator-expr.md b/src/expressions/operator-expr.md
@@ -470,6 +470,8 @@ fn example() {
 }
 ```
 
+Like assignment expressions, compound assignment expressions always produce [the unit value][unit].
+
 <div class="warning">
 
 Warning: The evaluation order of operands swaps depending on the types of the operands:

Original file line number	Diff line number	Diff line change
`@@ -470,6 +470,8 @@ fn example() {`
`470`	`470`	`}`
`471`	`471`	```
`472`	`472`
	`473`	`+Like assignment expressions, compound assignment expressions always produce [the unit value][unit].`
	`474`	`+`
`473`	`475`	`<div class="warning">`
`474`	`476`
`475`	`477`	`Warning: The evaluation order of operands swaps depending on the types of the operands:`