AnyCTO with arbitrary number of functions

Src/Base/AMReX_CTOParallelForImpl.H

@@ -44,24 +44,33 @@ namespace detail
         }
     };
 
-    template <class L, class F, typename... As>
+    template <class L, typename... As, class... Fs>
     bool
-    AnyCTO_helper2 (const L& l, const F& f, TypeList<As...>,
-                    std::array<int,sizeof...(As)> const& runtime_options)
+    AnyCTO_helper2 (const L& l, TypeList<As...>,
+                    std::array<int,sizeof...(As)> const& runtime_options, const Fs&...cto_functs)
     {
         if (runtime_options == std::array<int,sizeof...(As)>{As::value...}) {
-            l(CTOWrapper<F, As::value...>{f});
+            if constexpr (sizeof...(cto_functs) != 0) {
+                // Apply the CTOWrapper to each function that was given in cto_functs
+                // and call the CPU function l with all of them
+                l(CTOWrapper<Fs, As::value...>{cto_functs}...);
+            } else {
+                // No functions in cto_functs so we call l directly with the compile time arguments
+                l(As{}...);
+            }
             return true;
         } else {
             return false;
         }
     }
 
-    template <class L, class F, typename... PPs, typename RO>
+    template <class L, typename... PPs, typename RO, class...Fs>
     void
-    AnyCTO_helper1 (const L& l, const F& f, TypeList<PPs...>, RO const& runtime_options)
+    AnyCTO_helper1 (const L& l, TypeList<PPs...>,
+                    RO const& runtime_options, const Fs&...cto_functs)
     {
-        bool found_option = (false || ... || AnyCTO_helper2(l, f, PPs{}, runtime_options));
+        bool found_option = (false || ... ||
+                                AnyCTO_helper2(l, PPs{}, runtime_options, cto_functs...));
         amrex::ignore_unused(found_option);
         AMREX_ASSERT(found_option);
     }
@@ -168,17 +177,18 @@ namespace detail
  * \param list_of_compile_time_options list of all possible values of the parameters.
  * \param runtime_options the run time parameters.
  * \param l a callable object containing a CPU function that launches the provided GPU kernel.
- * \param f a callable object containing the GPU kernel with optimizations.
+ * \param cto_functs a callable object containing the GPU kernel with optimizations.
  */
-template <class L, class F, typename... CTOs>
+template <class L, class... Fs, typename... CTOs>
 void AnyCTO ([[maybe_unused]] TypeList<CTOs...> list_of_compile_time_options,
              std::array<int,sizeof...(CTOs)> const& runtime_options,
-             L&& l, F&& f)
+             L&& l, Fs&&...cto_functs)
 {
 #if (__cplusplus >= 201703L)
-    detail::AnyCTO_helper1(std::forward<L>(l), std::forward<F>(f),
+    detail::AnyCTO_helper1(std::forward<L>(l),
                            CartesianProduct(typename CTOs::list_type{}...),
-                           runtime_options);
+                           runtime_options,
+                           std::forward<Fs>(cto_functs)...);
 #else
     amrex::ignore_unused(runtime_options, l, f);
     static_assert(std::is_integral<F>::value, "This requires C++17");