From 234bc0c2374d83936fdf27093615df6f32a08107 Mon Sep 17 00:00:00 2001
From: Sam Atkins <atkinssj@serenityos.org>
Date: Thu, 24 Nov 2022 16:04:45 +0000
Subject: [PATCH] LibGfx: Prevent calling `to_type<T>()` on
 `Line/Point/Rect/Size<T>`

Also, add `Line::to_type<T>()` since that was missing.

Calling to_type() with the same type as the existing object accomplishes
nothing except wasting some cycles and making the code more verbose,
and it is hard to spot. Nobody does this in the code currently
(yay!) but I made this mistake repeatedly when doing my step-by-step
CSS Pixels conversion, so let's make it easier to catch them.
---
 Userland/Libraries/LibGfx/Line.h  | 7 +++++++
 Userland/Libraries/LibGfx/Point.h | 3 ++-
 Userland/Libraries/LibGfx/Rect.h  | 3 ++-
 Userland/Libraries/LibGfx/Size.h  | 3 ++-
 4 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/Userland/Libraries/LibGfx/Line.h b/Userland/Libraries/LibGfx/Line.h
index a4b07f23f5..3697eb0a59 100644
--- a/Userland/Libraries/LibGfx/Line.h
+++ b/Userland/Libraries/LibGfx/Line.h
@@ -134,6 +134,13 @@ public:
     void set_a(Point<T> const& a) { m_a = a; }
     void set_b(Point<T> const& b) { m_b = b; }
 
+    template<typename U>
+    requires(!IsSame<T, U>)
+        [[nodiscard]] ALWAYS_INLINE constexpr Line<U> to_type() const
+    {
+        return Line<U>(*this);
+    }
+
     String to_string() const;
 
 private:
diff --git a/Userland/Libraries/LibGfx/Point.h b/Userland/Libraries/LibGfx/Point.h
index 9ef99607fc..ce9fba7c28 100644
--- a/Userland/Libraries/LibGfx/Point.h
+++ b/Userland/Libraries/LibGfx/Point.h
@@ -229,7 +229,8 @@ public:
     [[nodiscard]] Point end_point_for_aspect_ratio(Point const& previous_end_point, float aspect_ratio) const;
 
     template<typename U>
-    [[nodiscard]] Point<U> to_type() const
+    requires(!IsSame<T, U>)
+        [[nodiscard]] Point<U> to_type() const
     {
         return Point<U>(*this);
     }
diff --git a/Userland/Libraries/LibGfx/Rect.h b/Userland/Libraries/LibGfx/Rect.h
index 493fe2fa03..99e6566913 100644
--- a/Userland/Libraries/LibGfx/Rect.h
+++ b/Userland/Libraries/LibGfx/Rect.h
@@ -949,7 +949,8 @@ public:
     }
 
     template<typename U>
-    [[nodiscard]] ALWAYS_INLINE Rect<U> to_type() const
+    requires(!IsSame<T, U>)
+        [[nodiscard]] ALWAYS_INLINE Rect<U> to_type() const
     {
         return Rect<U>(*this);
     }
diff --git a/Userland/Libraries/LibGfx/Size.h b/Userland/Libraries/LibGfx/Size.h
index 16f3a623e6..6e5931432c 100644
--- a/Userland/Libraries/LibGfx/Size.h
+++ b/Userland/Libraries/LibGfx/Size.h
@@ -176,7 +176,8 @@ public:
     }
 
     template<typename U>
-    [[nodiscard]] ALWAYS_INLINE constexpr Size<U> to_type() const
+    requires(!IsSame<T, U>)
+        [[nodiscard]] ALWAYS_INLINE constexpr Size<U> to_type() const
     {
         return Size<U>(*this);
     }