Fix ambiguous overload issue with Clang

Author: Morwenn

include/cpp-sort/sorter_facade.h

@@ -1405,6 +1405,24 @@ namespace cppsort
         }
     };
 
+    namespace detail
+    {
+        template<typename Iterator, typename... Args>
+        inline constexpr bool are_parameters_valid = false;
+
+        template<typename Iterator>
+        inline constexpr bool are_parameters_valid<Iterator> = true;
+
+        template<typename Iterator, typename Func>
+        inline constexpr bool are_parameters_valid<Iterator, Func>
+            = is_projection_iterator_v<std::identity, Iterator, Func> ||
+            is_projection_iterator_v<Func, Iterator, std::less<>>;
+
+        template<typename Iterator, typename Compare, typename Projection>
+        inline constexpr bool are_parameters_valid<Iterator, Compare, Projection>
+            = is_projection_iterator_v<Projection, Iterator, Compare>;
+    }
+
     template<typename Sorter>
     struct sorter_facade:
         sorter_facade_base<Sorter>
@@ -1418,6 +1436,7 @@ namespace cppsort
             typename... Args
         >
             requires mstd::permutable<Iterator>
+                && detail::are_parameters_valid<Iterator, Args...>
         constexpr auto operator()(this Self&& self, Iterator first, Sentinel last, Args&&... args)
             -> decltype(std::forward<Self>(self).sorter_facade_base<Sorter>::operator()(
                 std::move(first), std::move(last), std::forward<Args>(args)...
@@ -1434,6 +1453,7 @@ namespace cppsort
             typename... Args
         >
             requires mstd::permutable<mstd::iterator_t<Range>>
+                && detail::are_parameters_valid<mstd::iterator_t<Range>, Args...>
         constexpr auto operator()(this Self&& self, Range&& range, Args&&... args)
             -> decltype(std::forward<Self>(self).sorter_facade_base<Sorter>::operator()(
                 std::forward<Range>(range), std::forward<Args>(args)...