From c17aeb46b2119930ee68a16da9f072408c4a4414 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Mon, 13 Jan 2025 07:02:45 +0000
Subject: [PATCH 1/4] simplied gather signatures

---
 .../execution26/detail/gather_signatures.hpp   |  5 +++--
 .../beman/execution26/detail/meta_filter.hpp   | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/include/beman/execution26/detail/gather_signatures.hpp b/include/beman/execution26/detail/gather_signatures.hpp
index 9630e6ce..b8ce503c 100644
--- a/include/beman/execution26/detail/gather_signatures.hpp
+++ b/include/beman/execution26/detail/gather_signatures.hpp
@@ -23,6 +23,7 @@ struct same_tag<Tag, R(A...)> {
 };
 template <typename Tag>
 struct bound_tag {
+    using type = Tag;
     template <typename T>
     using predicate = ::beman::execution26::detail::same_tag<Tag, T>;
 };
@@ -70,12 +71,12 @@ template <typename Tag,
     requires requires {
         typename ::beman::execution26::detail::gather_signatures_helper<
             ::beman::execution26::detail::meta::
-                filter<::beman::execution26::detail::bound_tag<Tag>::template predicate, signatures>,
+                filter_tag<::beman::execution26::detail::same_tag, Tag, signatures>,
             Tuple,
             Variant>::type;
     }
 using gather_signatures = ::beman::execution26::detail::gather_signatures_helper<
-    ::beman::execution26::detail::meta::filter<::beman::execution26::detail::bound_tag<Tag>::template predicate,
+    ::beman::execution26::detail::meta::filter_tag<::beman::execution26::detail::same_tag, Tag,
                                                signatures>,
     Tuple,
     Variant>::type;
diff --git a/include/beman/execution26/detail/meta_filter.hpp b/include/beman/execution26/detail/meta_filter.hpp
index e77c3915..e9fe2c4b 100644
--- a/include/beman/execution26/detail/meta_filter.hpp
+++ b/include/beman/execution26/detail/meta_filter.hpp
@@ -13,21 +13,39 @@ namespace beman::execution26::detail::meta::detail {
 template <template <typename> class, typename>
 struct filter;
 
+template <template <typename, typename> class, typename, typename>
+struct filter_tag;
+
 template <template <typename> class Predicate, template <typename...> class List>
 struct filter<Predicate, List<>> {
     using type = List<>;
 };
 
+template <template <typename, typename> class Predicate, typename Tag, template <typename...> class List>
+struct filter_tag<Predicate, Tag, List<>> {
+    using type = List<>;
+};
+
 template <template <typename> class Predicate, template <typename...> class List, typename H, typename... T>
 struct filter<Predicate, List<H, T...>> {
     using tail = typename beman::execution26::detail::meta::detail::filter<Predicate, List<T...>>::type;
     using type = ::std::conditional_t<Predicate<H>::value, ::beman::execution26::detail::meta::prepend<H, tail>, tail>;
 };
+
+template <template <typename, typename> class Predicate, typename Tag, template <typename...> class List, typename H, typename... T>
+struct filter_tag<Predicate, Tag, List<H, T...>> {
+    using tail = typename beman::execution26::detail::meta::detail::filter_tag<Predicate, Tag, List<T...>>::type;
+    using type = ::std::conditional_t<Predicate<Tag, H>::value, ::beman::execution26::detail::meta::prepend<H, tail>, tail>;
+};
 } // namespace beman::execution26::detail::meta::detail
 
 namespace beman::execution26::detail::meta {
 template <template <typename> class Predicate, typename List>
 using filter = ::beman::execution26::detail::meta::detail::filter<Predicate, List>::type;
+
+template <template <typename, typename> class Predicate, typename Tag, typename List>
+using filter_tag = ::beman::execution26::detail::meta::detail::filter_tag<
+    Predicate, Tag, List>::type;
 }
 
 // ----------------------------------------------------------------------------

From 4ab7807c8c84c59915dddf146573b86bf22ba38b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Mon, 13 Jan 2025 07:04:21 +0000
Subject: [PATCH 2/4] clang-format

---
 .../beman/execution26/detail/gather_signatures.hpp   |  6 ++----
 include/beman/execution26/detail/meta_filter.hpp     | 12 ++++++++----
 tests/beman/execution26/CMakeLists.txt               |  2 +-
 3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/include/beman/execution26/detail/gather_signatures.hpp b/include/beman/execution26/detail/gather_signatures.hpp
index b8ce503c..7c65a2b3 100644
--- a/include/beman/execution26/detail/gather_signatures.hpp
+++ b/include/beman/execution26/detail/gather_signatures.hpp
@@ -70,14 +70,12 @@ template <typename Tag,
           template <typename...> class Variant>
     requires requires {
         typename ::beman::execution26::detail::gather_signatures_helper<
-            ::beman::execution26::detail::meta::
-                filter_tag<::beman::execution26::detail::same_tag, Tag, signatures>,
+            ::beman::execution26::detail::meta::filter_tag<::beman::execution26::detail::same_tag, Tag, signatures>,
             Tuple,
             Variant>::type;
     }
 using gather_signatures = ::beman::execution26::detail::gather_signatures_helper<
-    ::beman::execution26::detail::meta::filter_tag<::beman::execution26::detail::same_tag, Tag,
-                                               signatures>,
+    ::beman::execution26::detail::meta::filter_tag<::beman::execution26::detail::same_tag, Tag, signatures>,
     Tuple,
     Variant>::type;
 } // namespace beman::execution26::detail
diff --git a/include/beman/execution26/detail/meta_filter.hpp b/include/beman/execution26/detail/meta_filter.hpp
index e9fe2c4b..f3199161 100644
--- a/include/beman/execution26/detail/meta_filter.hpp
+++ b/include/beman/execution26/detail/meta_filter.hpp
@@ -32,10 +32,15 @@ struct filter<Predicate, List<H, T...>> {
     using type = ::std::conditional_t<Predicate<H>::value, ::beman::execution26::detail::meta::prepend<H, tail>, tail>;
 };
 
-template <template <typename, typename> class Predicate, typename Tag, template <typename...> class List, typename H, typename... T>
+template <template <typename, typename> class Predicate,
+          typename Tag,
+          template <typename...> class List,
+          typename H,
+          typename... T>
 struct filter_tag<Predicate, Tag, List<H, T...>> {
     using tail = typename beman::execution26::detail::meta::detail::filter_tag<Predicate, Tag, List<T...>>::type;
-    using type = ::std::conditional_t<Predicate<Tag, H>::value, ::beman::execution26::detail::meta::prepend<H, tail>, tail>;
+    using type =
+        ::std::conditional_t<Predicate<Tag, H>::value, ::beman::execution26::detail::meta::prepend<H, tail>, tail>;
 };
 } // namespace beman::execution26::detail::meta::detail
 
@@ -44,8 +49,7 @@ template <template <typename> class Predicate, typename List>
 using filter = ::beman::execution26::detail::meta::detail::filter<Predicate, List>::type;
 
 template <template <typename, typename> class Predicate, typename Tag, typename List>
-using filter_tag = ::beman::execution26::detail::meta::detail::filter_tag<
-    Predicate, Tag, List>::type;
+using filter_tag = ::beman::execution26::detail::meta::detail::filter_tag<Predicate, Tag, List>::type;
 }
 
 // ----------------------------------------------------------------------------
diff --git a/tests/beman/execution26/CMakeLists.txt b/tests/beman/execution26/CMakeLists.txt
index b9130f6e..0166c7e3 100644
--- a/tests/beman/execution26/CMakeLists.txt
+++ b/tests/beman/execution26/CMakeLists.txt
@@ -129,7 +129,7 @@ foreach(test ${execution_tests})
   add_test(NAME ${TEST_EXE} COMMAND $<TARGET_FILE:${TEST_EXE}>)
 endforeach()
 
-if(NOT PROJECT_IS_TOP_LEVEL)
+if(PROJECT_IS_TOP_LEVEL)
   # test if the targets are findable from the build directory
   # cmake-format: off
   add_test(NAME find-package-test

From acd343404e5b8ef259626d7240b87c0573d6b7e9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Mon, 13 Jan 2025 07:05:06 +0000
Subject: [PATCH 3/4] revert CMakeList.txt change

---
 tests/beman/execution26/CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/beman/execution26/CMakeLists.txt b/tests/beman/execution26/CMakeLists.txt
index 0166c7e3..b9130f6e 100644
--- a/tests/beman/execution26/CMakeLists.txt
+++ b/tests/beman/execution26/CMakeLists.txt
@@ -129,7 +129,7 @@ foreach(test ${execution_tests})
   add_test(NAME ${TEST_EXE} COMMAND $<TARGET_FILE:${TEST_EXE}>)
 endforeach()
 
-if(PROJECT_IS_TOP_LEVEL)
+if(NOT PROJECT_IS_TOP_LEVEL)
   # test if the targets are findable from the build directory
   # cmake-format: off
   add_test(NAME find-package-test

From 9c5ac2e88293ab57d6784c84d74fd206f1f67ded Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Mon, 13 Jan 2025 07:07:12 +0000
Subject: [PATCH 4/4] fixed formatting issue

---
 include/beman/execution26/detail/meta_filter.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/beman/execution26/detail/meta_filter.hpp b/include/beman/execution26/detail/meta_filter.hpp
index f3199161..d286e2ac 100644
--- a/include/beman/execution26/detail/meta_filter.hpp
+++ b/include/beman/execution26/detail/meta_filter.hpp
@@ -50,7 +50,7 @@ using filter = ::beman::execution26::detail::meta::detail::filter<Predicate, Lis
 
 template <template <typename, typename> class Predicate, typename Tag, typename List>
 using filter_tag = ::beman::execution26::detail::meta::detail::filter_tag<Predicate, Tag, List>::type;
-}
+} // namespace beman::execution26::detail::meta
 
 // ----------------------------------------------------------------------------