diff --git a/solutions/functional-programing/closure.md b/solutions/functional-programing/closure.md
index fd023da..034c507 100644
--- a/solutions/functional-programing/closure.md
+++ b/solutions/functional-programing/closure.md
@@ -118,7 +118,7 @@ fn main() {
 ```rust
 fn fn_once<F>(func: F)
 where
-    F: FnOnce(usize) -> bool + Copy,// 改动在这里
+    F: Copy + FnOnce(usize) -> bool,// 改动在这里
 {
     println!("{}", func(3));
     println!("{}", func(4));
@@ -293,4 +293,4 @@ fn factory(x:i32) -> Box<dyn Fn(i32) -> i32> {
 }
 
 fn main() {}
-```
\ No newline at end of file
+```