Make NodeArray monostate (not dependent on child relops)

Author: saki7

include/iris/compare.hpp

@@ -51,7 +51,8 @@ constexpr auto synth_three_way = []<class T, class U>(T const& t, U const& u) //
         { u < t } -> req::boolean_testable;
     }
 {
-    if constexpr (requires { t <=> u; } /*std::three_way_comparable_with<T, U>*/) {
+    if constexpr (std::three_way_comparable_with<T, U>) {
+    //if constexpr (requires { t <=> u; }) {
         return t <=> u;
     } else {
         if (t < u) return std::weak_ordering::less;

test/rvariant/truly_recursive_test.cpp

@@ -149,17 +149,37 @@ struct NodeArray
 
     bool operator==(NodeArray const& other) const
     {
-        return nodes == other.nodes;
+        return true;
+    }
+
+    bool operator!=(NodeArray const& other) const
+    {
+        return false;
     }
 
     bool operator<(NodeArray const& other) const
     {
-        return nodes < other.nodes;
+        return false;
+    }
+
+    bool operator<=(NodeArray const& other) const
+    {
+        return true;
+    }
+
+    bool operator>(NodeArray const& other) const
+    {
+        return false;
+    }
+
+    bool operator>=(NodeArray const& other) const
+    {
+        return true;
     }
 
-    auto operator<=>(NodeArray const& other) const
+    std::strong_ordering operator<=>(NodeArray const& other) const
     {
-        return nodes <=> other.nodes;
+        return std::strong_ordering::equivalent;
     }
 };