From b3cb64738bd1b873ec25a63f84e23050023b353b Mon Sep 17 00:00:00 2001
From: Arnaud Becheler <8360330+Becheler@users.noreply.github.com>
Date: Fri, 17 Jul 2026 10:58:26 +0200
Subject: [PATCH] refactor: remove dependency on boost.tti using detector idiom

---
 CMakeLists.txt                             |  1 -
 build.jam                                  |  1 -
 include/boost/graph/depth_first_search.hpp | 32 ++++++++++++----------
 3 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index cf2e99fbc..4099ab75e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -46,7 +46,6 @@ target_link_libraries(boost_graph
     Boost::smart_ptr
     Boost::spirit
     Boost::throw_exception
-    Boost::tti
     Boost::tuple
     Boost::type_traits
     Boost::unordered
diff --git a/build.jam b/build.jam
index c8f1b19af..511c1c7af 100644
--- a/build.jam
+++ b/build.jam
@@ -35,7 +35,6 @@ constant boost_dependencies :
     /boost/smart_ptr//boost_smart_ptr
     /boost/spirit//boost_spirit
     /boost/throw_exception//boost_throw_exception
-    /boost/tti//boost_tti
     /boost/tuple//boost_tuple
     /boost/type_traits//boost_type_traits
     /boost/unordered//boost_unordered
diff --git a/include/boost/graph/depth_first_search.hpp b/include/boost/graph/depth_first_search.hpp
index b42666cab..7b354c499 100644
--- a/include/boost/graph/depth_first_search.hpp
+++ b/include/boost/graph/depth_first_search.hpp
@@ -24,7 +24,8 @@
 #include <boost/optional.hpp>
 #include <boost/parameter.hpp>
 #include <boost/concept/assert.hpp>
-#include <boost/tti/has_member_function.hpp>
+#include <boost/type_traits/make_void.hpp>
+#include <type_traits>
 
 #include <vector>
 #include <utility>
@@ -68,7 +69,19 @@ namespace detail
         }
     };
 
-    BOOST_TTI_HAS_MEMBER_FUNCTION(finish_edge)
+    // has_finish_edge<Vis, E, G>::value is true when vis.finish_edge(e, g) is
+    // a valid call for e of type E and g of type const G&.
+    template < typename Vis, typename E, typename G, typename = void >
+    struct has_finish_edge : std::false_type
+    {
+    };
+    template < typename Vis, typename E, typename G >
+    struct has_finish_edge< Vis, E, G,
+        boost::void_t< decltype(std::declval< Vis& >().finish_edge(
+            std::declval< E& >(), std::declval< const G& >())) > >
+    : std::true_type
+    {
+    };
 
     template < bool IsCallable > struct do_call_finish_edge
     {
@@ -89,18 +102,9 @@ namespace detail
 
     template < typename E, typename G, typename Vis >
     void call_finish_edge(Vis& vis, E e, const G& g)
-    { // Only call if method exists
-#if ((defined(__GNUC__) && (__GNUC__ > 4)               \
-         || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 9))) \
-    || defined(__clang__)                               \
-    || (defined(__INTEL_COMPILER) && (__INTEL_COMPILER >= 1200)))
-        do_call_finish_edge< has_member_function_finish_edge< Vis, void,
-            boost::mpl::vector< E, const G& > >::value >::call_finish_edge(vis,
-            e, g);
-#else
-        do_call_finish_edge< has_member_function_finish_edge< Vis,
-            void >::value >::call_finish_edge(vis, e, g);
-#endif
+    { // Only call if the visitor has a callable finish_edge(e, g)
+        do_call_finish_edge< has_finish_edge< Vis, E, G >::value >::
+            call_finish_edge(vis, e, g);
     }
 
 // Define BOOST_RECURSIVE_DFS to use older, recursive version.