From acf341862aacc66204da13bca1063c18bb559710 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Fri, 12 Feb 2021 13:27:48 +0100
Subject: [PATCH] AK: Remove operators && and || from DistinctNumeric

These don't do short-circuit evaluation, and so I ran into some
some very subtle side-effects when converting code to DistinctNumeric.

In code like this:

    MyDistinctNumeric n;
    if (n && check_thing(n))
        return;

There would be no short-circuit evaluation if the return type of
check_thing() was implicitly convertible to MyDistinctNumeric.

Ran into this while making Ext2FS::GroupIndex a DistinctNumeric.
---
 AK/DistinctNumeric.h             | 10 ----------
 AK/Tests/TestDistinctNumeric.cpp |  9 ---------
 2 files changed, 19 deletions(-)

diff --git a/AK/DistinctNumeric.h b/AK/DistinctNumeric.h
index ae0c43f320e..dc679f88e77 100644
--- a/AK/DistinctNumeric.h
+++ b/AK/DistinctNumeric.h
@@ -150,16 +150,6 @@ public:
         static_assert(Bool, "'!a' is only available for DistinctNumeric types with 'Bool'.");
         return !this->m_value;
     }
-    bool operator&&(const Self& other) const
-    {
-        static_assert(Bool, "'a&&b' is only available for DistinctNumeric types with 'Bool'.");
-        return this->m_value && other.m_value;
-    }
-    bool operator||(const Self& other) const
-    {
-        static_assert(Bool, "'a||b' is only available for DistinctNumeric types with 'Bool'.");
-        return this->m_value || other.m_value;
-    }
     // Intentionally don't define `operator bool() const` here. C++ is a bit
     // overzealos, and whenever there would be a type error, C++ instead tries
     // to convert to a common int-ish type first. `bool` is int-ish, so
diff --git a/AK/Tests/TestDistinctNumeric.cpp b/AK/Tests/TestDistinctNumeric.cpp
index 0381bb55aad..83104754d60 100644
--- a/AK/Tests/TestDistinctNumeric.cpp
+++ b/AK/Tests/TestDistinctNumeric.cpp
@@ -123,13 +123,6 @@ TEST_CASE(operator_bool)
     EXPECT_EQ(!a, true);
     EXPECT_EQ(!b, false);
     EXPECT_EQ(!c, false);
-    EXPECT_EQ(a && b, false);
-    EXPECT_EQ(a && c, false);
-    EXPECT_EQ(b && c, true);
-    EXPECT_EQ(a || a, false);
-    EXPECT_EQ(a || b, true);
-    EXPECT_EQ(a || c, true);
-    EXPECT_EQ(b || c, true);
 }
 
 TEST_CASE(operator_flags)
@@ -233,8 +226,6 @@ TEST_CASE(composability)
     EXPECT_EQ(a >= b, false);
     // Bool
     EXPECT_EQ(!a, true);
-    EXPECT_EQ(a && b, false);
-    EXPECT_EQ(a || b, true);
     // Flags
     EXPECT_EQ(a & b, GeneralNumeric(0));
     EXPECT_EQ(a | b, GeneralNumeric(1));