From f2f590812504850b7e0031312804adf34260a474 Mon Sep 17 00:00:00 2001
From: Xun Li <lxfind@gmail.com>
Date: Tue, 21 Dec 2021 22:03:04 -0800
Subject: [PATCH] Use swap_or_fill

---
 fastx_programmability/framework/Move.toml          | 2 +-
 fastx_programmability/framework/examples/Hero.move | 9 +--------
 2 files changed, 2 insertions(+), 9 deletions(-)

diff --git a/fastx_programmability/framework/Move.toml b/fastx_programmability/framework/Move.toml
index ae6eb5b8bd8b4..f3c83208c85dd 100644
--- a/fastx_programmability/framework/Move.toml
+++ b/fastx_programmability/framework/Move.toml
@@ -3,7 +3,7 @@ name = "FastX"
 version = "0.0.1"
 
 [dependencies]
-MoveStdlib = { git = "https://github.com/diem/diem.git", subdir="language/move-stdlib", rev = "56ab033cc403b489e891424a629e76f643d4fb6b" }
+MoveStdlib = { git = "https://github.com/diem/diem.git", subdir="language/move-stdlib", rev = "5572eae5e35407f10316b473f95cb155a5e8d40b" }
 
 [addresses]
 Std = "0x1"
diff --git a/fastx_programmability/framework/examples/Hero.move b/fastx_programmability/framework/examples/Hero.move
index fe61011906ed4..bb11c791ecf66 100644
--- a/fastx_programmability/framework/examples/Hero.move
+++ b/fastx_programmability/framework/examples/Hero.move
@@ -163,14 +163,7 @@ module Examples::Hero {
     /// Add `new_sword` to the hero's inventory and return the old sword
     /// (if any)
     public fun equip_sword(hero: &mut Hero, new_sword: Sword): Option<Sword> {
-        // TODO: we should add a Option::swap_opt(&mut Option<T>, T): Option<T>
-        // that does this to the Move stdlib
-        if (Option::is_some(&hero.sword)) {
-            Option::some(Option::swap(&mut hero.sword, new_sword))
-        } else {
-            Option::fill(&mut hero.sword, new_sword);
-            Option::none<Sword>()
-        }
+        Option::swap_or_fill(&mut hero.sword, new_sword)
     }
 
     /// Disarm the hero by returning their sword.