diff --git a/00. TOP/01. TODO.md b/00. TOP/01. TODO.md
index cb5c384..9be0878 100644
--- a/00. TOP/01. TODO.md	
+++ b/00. TOP/01. TODO.md	
@@ -13,7 +13,7 @@
         - [std::ref 用法與範例 | ShengYu Talk](https://shengyu7697.github.io/std-ref/)
         - [multithreading - C++ reference wrapper as function argument - Stack Overflow](https://stackoverflow.com/questions/70516557/c-reference-wrapper-as-function-argument)
         - [c++ - Why does passing object reference arguments to thread function fails to compile? - Stack Overflow](https://stackoverflow.com/questions/8299545/why-does-passing-object-reference-arguments-to-thread-function-fails-to-compile)
-    - [ ] 好用的`std::optional` 🛫 2022-07-06
+    - [x] 好用的`std::optional` 🛫 2022-07-06 ✅ 2022-07-26
 - 試試看
     - [ ] [將照片隱藏在另一張照片中](https://avestura.dev/blog/hide-a-photo-inside-another-photo) 🛫 2022-07-06
     - [ ] Qt static build 🛫 2022-07-06