AK+Everywhere: Replace DistinctNumeric bool parameters with named ones

This means that rather than this:

```
AK_TYPEDEF_DISTINCT_NUMERIC_GENERAL(u64, true, true, false, false,
    false, true, FunctionAddress);
```

We now have this:
```
AK_TYPEDEF_DISTINCT_NUMERIC_GENERAL(u64, FunctionAddress, Arithmetic,
    Comparison, Increment);
```

Which is a lot more readable. :^)

Co-authored-by: Ali Mohammad Pur <mpfard@serenityos.org>

1 files changed, 104 insertions, 62 deletions

diff --git a/AK/DistinctNumeric.h b/AK/DistinctNumeric.h
index 38156f57d3..13ae37d5b5 100644
--- a/AK/DistinctNumeric.h
+++ b/AK/DistinctNumeric.h
@@ -1,6 +1,7 @@
 /*
  * Copyright (c) 2020, Ben Wiederhake <BenWiederhake.GitHub@gmx.de>
  * Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2022, Sam Atkins <atkinssj@serenityos.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -19,20 +20,19 @@ namespace AK {
  * want simply gets different values for `fn_length` and `line`. The macros
  * `TYPEDEF_DISTINCT_NUMERIC_*()` at the bottom of `DistinctNumeric.h`.
  *
- * `Incr`, `Cmp`, `Bool`, `Flags`, `Shift`, and `Arith` simply split up the
- * space of operators into 6 simple categories:
+ * The tags in `DistinctNumericFeature` simply split up the space of operators into 6 simple categories:
  * - No matter the values of these, `DistinctNumeric` always implements `==` and `!=`.
- * - If `Incr` is true, then `++a`, `a++`, `--a`, and `a--` are implemented.
- * - If `Cmp` is true, then `a>b`, `a<b`, `a>=b`, and `a<=b` are implemented.
- * - If `Bool` is true, then `!a`, `a&&b`, and `a||b` are implemented (but not `operator bool()`, because of overzealous integer promotion rules).
- * - If `Flags` is true, then `~a`, `a&b`, `a|b`, `a^b`, `a&=b`, `a|=b`, and `a^=b` are implemented.
- * - If `Shift` is true, then `a<<b`, `a>>b`, `a<<=b`, `a>>=b` are implemented.
- * - If `Arith` is true, then `a+b`, `a-b`, `+a`, `-a`, `a*b`, `a/b`, `a%b`, and the respective `a_=b` versions are implemented.
+ * - If `Arithmetic` is present, then `a+b`, `a-b`, `+a`, `-a`, `a*b`, `a/b`, `a%b`, and the respective `a_=b` versions are implemented.
+ * - If `CastToBool` is present, then `!a`, `a&&b`, and `a||b` are implemented (but not `operator bool()`, because of overzealous integer promotion rules).
+ * - If `Comparison` is present, then `a>b`, `a<b`, `a>=b`, and `a<=b` are implemented.
+ * - If `Flags` is present, then `~a`, `a&b`, `a|b`, `a^b`, `a&=b`, `a|=b`, and `a^=b` are implemented.
+ * - If `Increment` is present, then `++a`, `a++`, `--a`, and `a--` are implemented.
+ * - If `Shift` is present, then `a<<b`, `a>>b`, `a<<=b`, `a>>=b` are implemented.
  * The semantics are always those of the underlying basic type `T`.
  *
  * These can be combined arbitrarily. Want a numeric type that supports `++a`
  * and `a >> b` but not `a > b`? Sure thing, just set
- * `Incr=true, Cmp=false, Shift=true` and you're done!
+ * `Increment, Comparison, Shift` and you're done!
  * Furthermore, some of these overloads make more sense with specific types, like `a&&b` which should be able to operate
  *
  * I intentionally decided against overloading `&a` because these shall remain
@@ -47,9 +47,46 @@ namespace AK {
  * There are many more operators that do not make sense for numerical types,
  * or cannot be overloaded in the first place. Naturally, they are not implemented.
  */
-template<typename T, typename X, bool Incr, bool Cmp, bool Bool, bool Flags, bool Shift, bool Arith>
+
+namespace DistinctNumericFeature {
+enum Arithmetic {};
+enum CastToBool {};
+enum Comparison {};
+enum Flags {};
+enum Increment {};
+enum Shift {};
+};
+
+template<typename T, typename X, typename... Opts>
 class DistinctNumeric {
-    using Self = DistinctNumeric<T, X, Incr, Cmp, Bool, Flags, Shift, Arith>;
+    using Self = DistinctNumeric<T, X, Opts...>;
+
+    struct Option {
+        template<typename K, typename... Os>
+        consteval Option(K option, Os... other_options)
+            : Option(other_options...)
+        {
+            set(option);
+        }
+
+        consteval Option() { }
+
+        constexpr void set(DistinctNumericFeature::Arithmetic const&) { arithmetic = true; }
+        constexpr void set(DistinctNumericFeature::CastToBool const&) { cast_to_bool = true; }
+        constexpr void set(DistinctNumericFeature::Comparison const&) { comparisons = true; }
+        constexpr void set(DistinctNumericFeature::Flags const&) { flags = true; }
+        constexpr void set(DistinctNumericFeature::Increment const&) { increment = true; }
+        constexpr void set(DistinctNumericFeature::Shift const&) { shift = true; }
+
+        bool arithmetic { false };
+        bool cast_to_bool { false };
+        bool comparisons { false };
+        bool flags { false };
+        bool increment { false };
+        bool shift { false };
+    };
+
+    constexpr static Option options { Opts()... };
 
 public:
     constexpr DistinctNumeric() = default;
@@ -59,7 +96,7 @@ public:
     {
     }
 
-    constexpr const T& value() const { return m_value; }
+    constexpr T const& value() const { return m_value; }
     constexpr T& value() { return m_value; }
 
     // Always implemented: identity.
@@ -68,61 +105,61 @@ public:
         return this->m_value == other.m_value;
     }
 
-    // Only implemented when `Incr` is true:
+    // Only implemented when `Increment` is true:
     constexpr Self& operator++()
     {
-        static_assert(Incr, "'++a' is only available for DistinctNumeric types with 'Incr'.");
+        static_assert(options.increment, "'++a' is only available for DistinctNumeric types with 'Increment'.");
         this->m_value += 1;
         return *this;
     }
     constexpr Self operator++(int)
     {
-        static_assert(Incr, "'a++' is only available for DistinctNumeric types with 'Incr'.");
+        static_assert(options.increment, "'a++' is only available for DistinctNumeric types with 'Increment'.");
         Self ret = this->m_value;
         this->m_value += 1;
         return ret;
     }
     constexpr Self& operator--()
     {
-        static_assert(Incr, "'--a' is only available for DistinctNumeric types with 'Incr'.");
+        static_assert(options.increment, "'--a' is only available for DistinctNumeric types with 'Increment'.");
         this->m_value -= 1;
         return *this;
     }
     constexpr Self operator--(int)
     {
-        static_assert(Incr, "'a--' is only available for DistinctNumeric types with 'Incr'.");
+        static_assert(options.increment, "'a--' is only available for DistinctNumeric types with 'Increment'.");
         Self ret = this->m_value;
         this->m_value -= 1;
         return ret;
     }
 
-    // Only implemented when `Cmp` is true:
+    // Only implemented when `Comparison` is true:
     constexpr bool operator>(Self const& other) const
     {
-        static_assert(Cmp, "'a>b' is only available for DistinctNumeric types with 'Cmp'.");
+        static_assert(options.comparisons, "'a>b' is only available for DistinctNumeric types with 'Comparison'.");
         return this->m_value > other.m_value;
     }
     constexpr bool operator<(Self const& other) const
     {
-        static_assert(Cmp, "'a<b' is only available for DistinctNumeric types with 'Cmp'.");
+        static_assert(options.comparisons, "'a<b' is only available for DistinctNumeric types with 'Comparison'.");
         return this->m_value < other.m_value;
     }
     constexpr bool operator>=(Self const& other) const
     {
-        static_assert(Cmp, "'a>=b' is only available for DistinctNumeric types with 'Cmp'.");
+        static_assert(options.comparisons, "'a>=b' is only available for DistinctNumeric types with 'Comparison'.");
         return this->m_value >= other.m_value;
     }
     constexpr bool operator<=(Self const& other) const
     {
-        static_assert(Cmp, "'a<=b' is only available for DistinctNumeric types with 'Cmp'.");
+        static_assert(options.comparisons, "'a<=b' is only available for DistinctNumeric types with 'Comparison'.");
         return this->m_value <= other.m_value;
     }
     // 'operator<=>' cannot be implemented. See class comment.
 
-    // Only implemented when `bool` is true:
+    // Only implemented when `CastToBool` is true:
     constexpr bool operator!() const
     {
-        static_assert(Bool, "'!a' is only available for DistinctNumeric types with 'Bool'.");
+        static_assert(options.cast_to_bool, "'!a' is only available for DistinctNumeric types with 'CastToBool'.");
         return !this->m_value;
     }
     // Intentionally don't define `operator bool() const` here. C++ is a bit
@@ -133,39 +170,39 @@ public:
     // Only implemented when `Flags` is true:
     constexpr Self operator~() const
     {
-        static_assert(Flags, "'~a' is only available for DistinctNumeric types with 'Flags'.");
+        static_assert(options.flags, "'~a' is only available for DistinctNumeric types with 'Flags'.");
         return ~this->m_value;
     }
     constexpr Self operator&(Self const& other) const
     {
-        static_assert(Flags, "'a&b' is only available for DistinctNumeric types with 'Flags'.");
+        static_assert(options.flags, "'a&b' is only available for DistinctNumeric types with 'Flags'.");
         return this->m_value & other.m_value;
     }
     constexpr Self operator|(Self const& other) const
     {
-        static_assert(Flags, "'a|b' is only available for DistinctNumeric types with 'Flags'.");
+        static_assert(options.flags, "'a|b' is only available for DistinctNumeric types with 'Flags'.");
         return this->m_value | other.m_value;
     }
     constexpr Self operator^(Self const& other) const
     {
-        static_assert(Flags, "'a^b' is only available for DistinctNumeric types with 'Flags'.");
+        static_assert(options.flags, "'a^b' is only available for DistinctNumeric types with 'Flags'.");
         return this->m_value ^ other.m_value;
     }
     constexpr Self& operator&=(Self const& other)
     {
-        static_assert(Flags, "'a&=b' is only available for DistinctNumeric types with 'Flags'.");
+        static_assert(options.flags, "'a&=b' is only available for DistinctNumeric types with 'Flags'.");
         this->m_value &= other.m_value;
         return *this;
     }
     constexpr Self& operator|=(Self const& other)
     {
-        static_assert(Flags, "'a|=b' is only available for DistinctNumeric types with 'Flags'.");
+        static_assert(options.flags, "'a|=b' is only available for DistinctNumeric types with 'Flags'.");
         this->m_value |= other.m_value;
         return *this;
     }
     constexpr Self& operator^=(Self const& other)
     {
-        static_assert(Flags, "'a^=b' is only available for DistinctNumeric types with 'Flags'.");
+        static_assert(options.flags, "'a^=b' is only available for DistinctNumeric types with 'Flags'.");
         this->m_value ^= other.m_value;
         return *this;
     }
@@ -174,90 +211,90 @@ public:
     // TODO: Should this take `int` instead?
     constexpr Self operator<<(Self const& other) const
     {
-        static_assert(Shift, "'a<<b' is only available for DistinctNumeric types with 'Shift'.");
+        static_assert(options.shift, "'a<<b' is only available for DistinctNumeric types with 'Shift'.");
         return this->m_value << other.m_value;
     }
     constexpr Self operator>>(Self const& other) const
     {
-        static_assert(Shift, "'a>>b' is only available for DistinctNumeric types with 'Shift'.");
+        static_assert(options.shift, "'a>>b' is only available for DistinctNumeric types with 'Shift'.");
         return this->m_value >> other.m_value;
     }
     constexpr Self& operator<<=(Self const& other)
     {
-        static_assert(Shift, "'a<<=b' is only available for DistinctNumeric types with 'Shift'.");
+        static_assert(options.shift, "'a<<=b' is only available for DistinctNumeric types with 'Shift'.");
         this->m_value <<= other.m_value;
         return *this;
     }
     constexpr Self& operator>>=(Self const& other)
     {
-        static_assert(Shift, "'a>>=b' is only available for DistinctNumeric types with 'Shift'.");
+        static_assert(options.shift, "'a>>=b' is only available for DistinctNumeric types with 'Shift'.");
         this->m_value >>= other.m_value;
         return *this;
     }
 
-    // Only implemented when `Arith` is true:
+    // Only implemented when `Arithmetic` is true:
     constexpr Self operator+(Self const& other) const
     {
-        static_assert(Arith, "'a+b' is only available for DistinctNumeric types with 'Arith'.");
+        static_assert(options.arithmetic, "'a+b' is only available for DistinctNumeric types with 'Arithmetic'.");
         return this->m_value + other.m_value;
     }
     constexpr Self operator-(Self const& other) const
     {
-        static_assert(Arith, "'a-b' is only available for DistinctNumeric types with 'Arith'.");
+        static_assert(options.arithmetic, "'a-b' is only available for DistinctNumeric types with 'Arithmetic'.");
         return this->m_value - other.m_value;
     }
     constexpr Self operator+() const
     {
-        static_assert(Arith, "'+a' is only available for DistinctNumeric types with 'Arith'.");
+        static_assert(options.arithmetic, "'+a' is only available for DistinctNumeric types with 'Arithmetic'.");
         return +this->m_value;
     }
     constexpr Self operator-() const
     {
-        static_assert(Arith, "'-a' is only available for DistinctNumeric types with 'Arith'.");
+        static_assert(options.arithmetic, "'-a' is only available for DistinctNumeric types with 'Arithmetic'.");
         return -this->m_value;
     }
     constexpr Self operator*(Self const& other) const
     {
-        static_assert(Arith, "'a*b' is only available for DistinctNumeric types with 'Arith'.");
+        static_assert(options.arithmetic, "'a*b' is only available for DistinctNumeric types with 'Arithmetic'.");
         return this->m_value * other.m_value;
     }
     constexpr Self operator/(Self const& other) const
     {
-        static_assert(Arith, "'a/b' is only available for DistinctNumeric types with 'Arith'.");
+        static_assert(options.arithmetic, "'a/b' is only available for DistinctNumeric types with 'Arithmetic'.");
         return this->m_value / other.m_value;
     }
     constexpr Self operator%(Self const& other) const
     {
-        static_assert(Arith, "'a%b' is only available for DistinctNumeric types with 'Arith'.");
+        static_assert(options.arithmetic, "'a%b' is only available for DistinctNumeric types with 'Arithmetic'.");
         return this->m_value % other.m_value;
     }
     constexpr Self& operator+=(Self const& other)
     {
-        static_assert(Arith, "'a+=b' is only available for DistinctNumeric types with 'Arith'.");
+        static_assert(options.arithmetic, "'a+=b' is only available for DistinctNumeric types with 'Arithmetic'.");
         this->m_value += other.m_value;
         return *this;
     }
     constexpr Self& operator-=(Self const& other)
     {
-        static_assert(Arith, "'a+=b' is only available for DistinctNumeric types with 'Arith'.");
+        static_assert(options.arithmetic, "'a+=b' is only available for DistinctNumeric types with 'Arithmetic'.");
         this->m_value += other.m_value;
         return *this;
     }
     constexpr Self& operator*=(Self const& other)
     {
-        static_assert(Arith, "'a*=b' is only available for DistinctNumeric types with 'Arith'.");
+        static_assert(options.arithmetic, "'a*=b' is only available for DistinctNumeric types with 'Arithmetic'.");
         this->m_value *= other.m_value;
         return *this;
     }
     constexpr Self& operator/=(Self const& other)
     {
-        static_assert(Arith, "'a/=b' is only available for DistinctNumeric types with 'Arith'.");
+        static_assert(options.arithmetic, "'a/=b' is only available for DistinctNumeric types with 'Arithmetic'.");
         this->m_value /= other.m_value;
         return *this;
     }
     constexpr Self& operator%=(Self const& other)
     {
-        static_assert(Arith, "'a%=b' is only available for DistinctNumeric types with 'Arith'.");
+        static_assert(options.arithmetic, "'a%=b' is only available for DistinctNumeric types with 'Arithmetic'.");
         this->m_value %= other.m_value;
         return *this;
     }
@@ -266,29 +303,34 @@ private:
     T m_value {};
 };
 
-template<typename T, typename X, bool Incr, bool Cmp, bool Bool, bool Flags, bool Shift, bool Arith>
-struct Formatter<DistinctNumeric<T, X, Incr, Cmp, Bool, Flags, Shift, Arith>> : Formatter<T> {
-    ErrorOr<void> format(FormatBuilder& builder, DistinctNumeric<T, X, Incr, Cmp, Bool, Flags, Shift, Arith> value)
+template<typename T, typename X, typename... Opts>
+struct Formatter<DistinctNumeric<T, X, Opts...>> : Formatter<T> {
+    ErrorOr<void> format(FormatBuilder& builder, DistinctNumeric<T, X, Opts...> value)
     {
         return Formatter<T>::format(builder, value.value());
     }
 };
-
-// TODO: When 'consteval' sufficiently-well supported by host compilers, try to
-// provide a more usable interface like this one:
-// https://gist.github.com/alimpfard/a3b750e8c3a2f44fb3a2d32038968ddf
-
 }
 
-#define AK_TYPEDEF_DISTINCT_NUMERIC_GENERAL(T, Incr, Cmp, Bool, Flags, Shift, Arith, NAME) \
-    using NAME = DistinctNumeric<T, struct __##NAME##_tag, Incr, Cmp, Bool, Flags, Shift, Arith>;
-#define AK_TYPEDEF_DISTINCT_ORDERED_ID(T, NAME) AK_TYPEDEF_DISTINCT_NUMERIC_GENERAL(T, false, true, true, false, false, false, NAME)
+#define AK_TYPEDEF_DISTINCT_NUMERIC_GENERAL(T, NAME, ...)                                       \
+    struct NAME##_decl {                                                                        \
+        using Arithmetic [[maybe_unused]] = AK::DistinctNumericFeature::Arithmetic;             \
+        using CastToBool [[maybe_unused]] = AK::DistinctNumericFeature::CastToBool;             \
+        using Comparison [[maybe_unused]] = AK::DistinctNumericFeature::Comparison;             \
+        using Flags [[maybe_unused]] = AK::DistinctNumericFeature::Flags;                       \
+        using Increment [[maybe_unused]] = AK::DistinctNumericFeature::Increment;               \
+        using Shift [[maybe_unused]] = AK::DistinctNumericFeature::Shift;                       \
+        using NAME [[maybe_unused]] = DistinctNumeric<T, struct __##NAME##_tag, ##__VA_ARGS__>; \
+    };                                                                                          \
+    using NAME = typename NAME##_decl::NAME;
+
+#define AK_TYPEDEF_DISTINCT_ORDERED_ID(T, NAME) AK_TYPEDEF_DISTINCT_NUMERIC_GENERAL(T, NAME, Comparison, CastToBool)
 // TODO: Further type aliases?
 
-template<typename T, typename X, auto... Args>
-struct Traits<AK::DistinctNumeric<T, X, Args...>> : public GenericTraits<AK::DistinctNumeric<T, X, Args...>> {
+template<typename T, typename X, typename... Opts>
+struct Traits<AK::DistinctNumeric<T, X, Opts...>> : public GenericTraits<AK::DistinctNumeric<T, X, Opts...>> {
     static constexpr bool is_trivial() { return true; }
-    static constexpr auto hash(DistinctNumeric<T, X, Args...> const& d) { return Traits<T>::hash(d.value()); }
+    static constexpr auto hash(DistinctNumeric<T, X, Opts...> const& d) { return Traits<T>::hash(d.value()); }
 };
 
 using AK::DistinctNumeric;