moved iterators to operator<=> and operator==

include/emlabcpp/iterator.h

@@ -82,10 +82,9 @@ class generic_iterator {
                 return copy;
         }
 
-        constexpr bool operator<(const generic_iterator<Derived> &other) const {
-                return impl() < other.impl();
+        constexpr auto operator<=>(const generic_iterator<Derived> &other) const {
+                return impl() <=> other.impl();
         }
-
         constexpr bool operator==(const generic_iterator<Derived> &other) const {
                 return impl() == other.impl();
         }
@@ -103,31 +102,4 @@ class generic_iterator {
         }
 };
 
-/// A > B iff B < A
-template <typename Derived>
-constexpr bool operator>(const generic_iterator<Derived> &lh, const generic_iterator<Derived> &rh) {
-        return rh < lh;
-}
-
-/// A <= B iff !( B > A )
-template <typename Derived>
-constexpr bool operator<=(const generic_iterator<Derived> &lh,
-                          const generic_iterator<Derived> &rh) {
-        return !(lh > rh);
-}
-
-/// A >= B iff !( B < A )
-template <typename Derived>
-constexpr bool operator>=(const generic_iterator<Derived> &lh,
-                          const generic_iterator<Derived> &rh) {
-        return !(lh < rh);
-}
-
-/// A != B iff !( A == B)
-template <typename Derived>
-constexpr bool operator!=(const generic_iterator<Derived> &lh,
-                          const generic_iterator<Derived> &rh) {
-        return !(lh == rh);
-}
-
 } // namespace emlabcpp

include/emlabcpp/iterators/access.h

@@ -49,8 +49,8 @@ class access_iterator : public generic_iterator<access_iterator<Iterator, Access
                 return *this;
         }
 
-        constexpr bool operator<(const access_iterator &other) const {
-                return current_ < other.current_;
+        constexpr auto operator<=>(const access_iterator &other) const {
+                return current_ <=> other.current_;
         }
         constexpr bool operator==(const access_iterator &other) const {
                 return current_ == other.current_;

include/emlabcpp/iterators/numeric.h

@@ -45,8 +45,10 @@ class numeric_iterator : public generic_iterator<numeric_iterator<T>> {
                 return *this;
         }
 
-        constexpr bool operator<(const numeric_iterator &other) const { return val_ < other.val_; }
-        constexpr bool operator==(const numeric_iterator &other) const {
+        constexpr auto operator<=>(const numeric_iterator<T> &other) const {
+                return val_ <=> other.val_;
+        }
+        constexpr auto operator==(const numeric_iterator<T> &other) const {
                 return val_ == other.val_;
         }
 

include/emlabcpp/iterators/subscript.h

@@ -51,7 +51,7 @@ class subscript_iterator : public generic_iterator<subscript_iterator<Container>
                 return *this;
         }
 
-        bool operator<(const subscript_iterator &other) const { return i_ < other.i_; }
+        auto operator<=>(const subscript_iterator &other) const { return i_ <=> other.i_; }
         bool operator==(const subscript_iterator &other) const {
                 return i_ == other.i_ && &cont_ == &other.cont_;
         }