From 0d8c9024eec12d57270cca1cf6bfc7d03c0ca229 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Thu, 18 Mar 2021 21:50:52 +0100
Subject: [PATCH] LibWeb: Add fast_is<T> for CSSRule subclasses

Since we already have a type enum for these, let's use it to make
is<T> bypass dynamic_cast for CSS rules.

These were often near the top of random browser profiles.
---
 Userland/Libraries/LibWeb/CSS/CSSImportRule.h | 3 +++
 Userland/Libraries/LibWeb/CSS/CSSRule.h       | 3 +++
 Userland/Libraries/LibWeb/CSS/CSSStyleRule.h  | 3 +++
 3 files changed, 9 insertions(+)

diff --git a/Userland/Libraries/LibWeb/CSS/CSSImportRule.h b/Userland/Libraries/LibWeb/CSS/CSSImportRule.h
index 2c752daab7..e097f80888 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSImportRule.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSImportRule.h
@@ -60,4 +60,7 @@ private:
     RefPtr<CSSStyleSheet> m_style_sheet;
 };
 
+template<>
+inline bool CSSRule::fast_is<CSSImportRule>() const { return type() == CSSRule::Type::Import; }
+
 }
diff --git a/Userland/Libraries/LibWeb/CSS/CSSRule.h b/Userland/Libraries/LibWeb/CSS/CSSRule.h
index 63fa5c1868..d7f3b51eeb 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSRule.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSRule.h
@@ -47,6 +47,9 @@ public:
     virtual StringView class_name() const = 0;
     virtual Type type() const = 0;
 
+    template<typename T>
+    bool fast_is() const = delete;
+
 private:
 };
 
diff --git a/Userland/Libraries/LibWeb/CSS/CSSStyleRule.h b/Userland/Libraries/LibWeb/CSS/CSSStyleRule.h
index e8db816f6c..abee9ce941 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSStyleRule.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSStyleRule.h
@@ -59,4 +59,7 @@ private:
     NonnullRefPtr<CSSStyleDeclaration> m_declaration;
 };
 
+template<>
+inline bool CSSRule::fast_is<CSSStyleRule>() const { return type() == CSSRule::Type::Style; }
+
 }