From efc8cbff521a9367ae30189e8b0e5ee62152d19f Mon Sep 17 00:00:00 2001
From: Jean-Louis Leroy <jl@leroy.nyc>
Date: Mon, 26 May 2025 15:19:55 -0400
Subject: [PATCH] add method::has_next, and have macros delegate to it

---
 include/boost/openmethod/core.hpp   | 11 +++++++++++
 include/boost/openmethod/macros.hpp |  5 ++---
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/include/boost/openmethod/core.hpp b/include/boost/openmethod/core.hpp
index f6bbbb6..d364b11 100644
--- a/include/boost/openmethod/core.hpp
+++ b/include/boost/openmethod/core.hpp
@@ -1046,6 +1046,9 @@ class method<Name, auto(Parameters...)->ReturnType, Registry>
     template<auto>
     static function_type next;
 
+    template<auto>
+    static bool has_next();
+
     static BOOST_NORETURN auto
     not_implemented_handler(detail::remove_virtual<Parameters>... args)
         -> ReturnType;
@@ -1354,6 +1357,14 @@ auto error_type_id(const Class& obj) {
 
 } // namespace detail
 
+template<
+    typename Name, typename... Parameters, typename ReturnType, class Registry>
+template<auto Fn>
+inline auto method<Name, auto(Parameters...)->ReturnType, Registry>::has_next()
+    -> bool {
+    return next<Fn> != not_implemented_handler;
+}
+
 template<
     typename Name, typename... Parameters, typename ReturnType, class Registry>
 BOOST_NORETURN auto method<Name, auto(Parameters...)->ReturnType, Registry>::
diff --git a/include/boost/openmethod/macros.hpp b/include/boost/openmethod/macros.hpp
index 316f21c..26ad774 100644
--- a/include/boost/openmethod/macros.hpp
+++ b/include/boost/openmethod/macros.hpp
@@ -115,9 +115,8 @@ struct va_args<ReturnType> {
     };                                                                         \
     inline auto BOOST_OPENMETHOD_OVERRIDERS(                                   \
         NAME)<__VA_ARGS__ ARGS>::has_next() -> bool {                          \
-        using method_type =                                                    \
-            boost_openmethod_detail_locate_method_aux<void ARGS>::type;        \
-        return method_type::next<fn> != method_type::not_implemented_handler;  \
+        return boost_openmethod_detail_locate_method_aux<                      \
+            void ARGS>::type::has_next<fn>();                                  \
     }                                                                          \
     template<typename... Args>                                                 \
     inline auto BOOST_OPENMETHOD_OVERRIDERS(NAME)<__VA_ARGS__ ARGS>::next(     \