Auto-generation of comparisons as a capability.

auto_comparable.h

@@ -0,0 +1,35 @@
+static_assert( __cplusplus > 2020'00 );
+
+#pragma once
+
+#include <Alepha/Alepha.h>
+
+#include <Alepha/Capabilities.h>
+#include <Alepha/comparisons.h>
+
+#include <Alepha/Reflection/tuplizeAggregate.h>
+
+namespace Alepha::Hydrogen  ::detail::  auto_comparable_module
+{
+	inline namespace exports
+	{
+		struct auto_comparable : comparable {};
+	}
+
+	template< typename T >
+	concept AutoComparableAggregate=
+		Capability< T, auto_comparable >
+			and
+		Aggregate< T >;
+
+	constexpr decltype( auto )
+	equality_lens( const AutoComparableAggregate auto &item ) noexcept
+	{
+		return detail::comparisons::magma_hook{ Reflection::tuplizeAggregate( item ) };
+	}
+}
+
+namespace Alepha::Hydrogen::inline exports::inline auto_comparable_module
+{
+	using namespace detail::auto_comparable_module::exports;
+}