1 files changed, 60 insertions, 15 deletions
diff --git a/src/libutil/comparator.hh b/src/libutil/comparator.hh
index eecd5b819..a4d20a675 100644
--- a/src/libutil/comparator.hh
+++ b/src/libutil/comparator.hh
@@ -1,6 +1,51 @@
 #pragma once
+///@file
 
-/* Awfull hacky generation of the comparison operators by doing a lexicographic
+#define DECLARE_ONE_CMP(PRE, QUAL, COMPARATOR, MY_TYPE) \
+    PRE bool QUAL operator COMPARATOR(const MY_TYPE & other) const;
+#define DECLARE_EQUAL(prefix, qualification, my_type) \
+    DECLARE_ONE_CMP(prefix, qualification, ==, my_type)
+#define DECLARE_LEQ(prefix, qualification, my_type) \
+    DECLARE_ONE_CMP(prefix, qualification, <, my_type)
+#define DECLARE_NEQ(prefix, qualification, my_type) \
+    DECLARE_ONE_CMP(prefix, qualification, !=, my_type)
+
+#define GENERATE_ONE_CMP(PRE, QUAL, COMPARATOR, MY_TYPE, ...) \
+    PRE bool QUAL operator COMPARATOR(const MY_TYPE & other) const { \
+      __VA_OPT__(const MY_TYPE * me = this;) \
+      auto fields1 = std::make_tuple( __VA_ARGS__ ); \
+      __VA_OPT__(me = &other;) \
+      auto fields2 = std::make_tuple( __VA_ARGS__ ); \
+      return fields1 COMPARATOR fields2; \
+    }
+#define GENERATE_EQUAL(prefix, qualification, my_type, args...) \
+    GENERATE_ONE_CMP(prefix, qualification, ==, my_type, args)
+#define GENERATE_LEQ(prefix, qualification, my_type, args...) \
+    GENERATE_ONE_CMP(prefix, qualification, <, my_type, args)
+#define GENERATE_NEQ(prefix, qualification, my_type, args...) \
+    GENERATE_ONE_CMP(prefix, qualification, !=, my_type, args)
+
+/**
+ * Declare comparison methods without defining them.
+ */
+#define DECLARE_CMP(my_type) \
+    DECLARE_EQUAL(,,my_type) \
+    DECLARE_LEQ(,,my_type) \
+    DECLARE_NEQ(,,my_type)
+
+/**
+ * @param prefix This is for something before each declaration like
+ * `template<classname Foo>`.
+ *
+ * @param my_type the type are defining operators for.
+ */
+#define DECLARE_CMP_EXT(prefix, qualification, my_type) \
+    DECLARE_EQUAL(prefix, qualification, my_type) \
+    DECLARE_LEQ(prefix, qualification, my_type) \
+    DECLARE_NEQ(prefix, qualification, my_type)
+
+/**
+ * Awful hacky generation of the comparison operators by doing a lexicographic
  * comparison between the choosen fields.
  *
  * ```
@@ -15,18 +60,18 @@
  * }
  * ```
  */
-#define GENERATE_ONE_CMP(COMPARATOR, MY_TYPE, FIELDS...) \
-    bool operator COMPARATOR(const MY_TYPE& other) const { \
-      const MY_TYPE* me = this; \
-      auto fields1 = std::make_tuple( FIELDS ); \
-      me = &other; \
-      auto fields2 = std::make_tuple( FIELDS ); \
-      return fields1 COMPARATOR fields2; \
-    }
-#define GENERATE_EQUAL(args...) GENERATE_ONE_CMP(==, args)
-#define GENERATE_LEQ(args...) GENERATE_ONE_CMP(<, args)
-#define GENERATE_NEQ(args...) GENERATE_ONE_CMP(!=, args)
 #define GENERATE_CMP(args...) \
-    GENERATE_EQUAL(args) \
-    GENERATE_LEQ(args) \
-    GENERATE_NEQ(args)
+    GENERATE_EQUAL(,,args) \
+    GENERATE_LEQ(,,args) \
+    GENERATE_NEQ(,,args)
+
+/**
+ * @param prefix This is for something before each declaration like
+ * `template<classname Foo>`.
+ *
+ * @param my_type the type are defining operators for.
+ */
+#define GENERATE_CMP_EXT(prefix, my_type, args...) \
+    GENERATE_EQUAL(prefix, my_type ::, my_type, args) \
+    GENERATE_LEQ(prefix, my_type ::, my_type, args) \
+    GENERATE_NEQ(prefix, my_type ::, my_type, args)