From d81186c2084f8e1fc675daa7ad98a85c64faaf22 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C3=A9o=20Lam?= <leo@leolam.fr>
Date: Thu, 9 Sep 2021 22:37:42 +0200
Subject: [PATCH] cheatsheet: Add sead::DynamicCast

---
 Cheatsheet.md | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/Cheatsheet.md b/Cheatsheet.md
index 8e2f1517..65576975 100644
--- a/Cheatsheet.md
+++ b/Cheatsheet.md
@@ -369,6 +369,32 @@ item = buffer[i];
 
 ---
 
+#### RTTI (Runtime Type Info)
+
+##### sead::DynamicCast
+
+```cpp
+some_ptr = ...;
+x = __ldar(...);  // usually a guard variable, but the variable is not always named
+another_ptr = some_ptr;
+if ( (x & 1) == 0 && _cxa_guard_acquire_0(...))  // the same guard variable
+{
+  ... = &...;
+  _cxa_guard_release_0(...);  // the same guard variable
+}
+if ( another_ptr && another_ptr->checkDerivedRuntimeTypeInfo(another_ptr, ...) )
+{
+  // code that uses another_ptr
+}
+```
+⬇️
+```cpp
+if (auto* another_ptr = sead::DynamicCast<T>(some_ptr))
+  ...
+```
+
+T is a derived type that should be related to the type of the original pointer.
+
 ### agl
 
 agl is one of Nintendo's in-house graphics libraries.